Super Set 3
5 Advantages of Multi-vari Studies
5 Advantages of Multi-vari Studies 1) Can dramatize the variation within the piece (positional) 2) Can dramatize the variation from piece to piece (cyclical) 3) Help track any time-related changes (Temporal) 4) Minimizes variation by identifying areas to look for excessive variation 5) Identifies areas not to look for excessive variation.
5 Advantages of Multi-variant Studies
5 Advantages of Multi-variant Studies 1) Can dramatize variation within the piece (positional) 2) Can dramatize the variation from piece to piece (cyclical) 3) Helps to track any time related changes (temporal) 4) Minimizes variation by identifying areas to look for excessive variation 5) Identifies areas not to look for excessive variation.
Activity Network Diagrams
Activity Network Diagrams 1) Methodology that includes program evaluation and review PERT, critical path methods, node/ activity on node diagram (AON), precedence diagrams, and other network diagrams 2) Lot of PERT and CPM techniques in usage---to help monitor, schedule, modify, and reciew projects.
After implementation of TPM, wha tis the long-term objective?
After implementation of TPM, wha tis the long-term objective? Perfection
An organized and disciplined approach to problem-solving in most six sigma organizations is called: A. SIPOC B. DMAIC C. PDCA D. DPMO
An organized and disciplined approach to problem-solving in most six sigma organization is called: A. SIPOC B. DMAIC C. PDCA D. DPMO B= CORRECT... Only two problem-solving approaches listed are DMAIC and PDCA. DMAIC is most closely linked with 6 sigma. PDCA is team-problem solving toll. Section II-4
Analysis of Variance Method
Analysis of Variance Method Most accurate method for quantifying repeatability and reproducibility that still allows the variability of interaction between appraisers and the parts to be determined
Basic objective of visual factory technique is?
Basic objective of visual factory technique is? enable everyone to maintain contact with the workplace. --- Visual factory technique make problems visible
Difference between absolute value and true value with respect to a standard master at various measurement point of the measuring range
Bias Difference between absolute value and true value with respect to a standard master at various measurement point of the measuring range
Bias in R& R Study is reported as:
Bias in R& R Study is reported as: percentage of process variation or tolerance.
Box-And-Wisker Plot
Box-And-Wicker Plot 1) Indicates variability of the median 2) Whiskers = min and max data point at the end of the lines extending from the box 3) Data median= line dividing the box 4) Asterics= outliner data (Make sure you can label the parts)
Drift in average measurements of an absolute value
Calibration Drift in average measurements of an absolute value
Components of Activity Network Diagrams
Components of Activity Network Diagrams 1) Event, node= junction point 2) Dummy note= combines the relative timing of parlay operations 3) Critical path = path with longest time 4) Slack time= difference b/w earliest finish time and latest time.
Concept behind PCDA is: 1) Deming/Shewart Cycle 2) Process Flow 3) Continuous Improvement 4) Satisfying suppliers
Concept behind PCDA is: 1) Deming/Shewart Cycle 2) Process Flow 3) Continuous Improvement 4) Satisfying suppliers 3--correct
Decision Rules for concluding process is out-of-control
Decision Rules for concluding process is out-of-control: 1) One point plots outside the 3-sigma control limits 2) Two out of 3 consecutive points plot outside the 2-sigma warning limits 3) 4 out of the 5 consecutive points plot outside of the 1-sigma limit 4) 8 consecutive points plot on one side of the center line.
Drawback of Projects Under Consideration
Drawback of Projects Under Consideration 1) May conflict with customer needs, industry standards, product specification, personnel safely or laws/ regulatory requirements
Effective project planning requires 7 skills
Effective project planning requires 7 skills 1) Information processing 2) Communication 3) Resource negotiations 4) Securing commitments 5) Incremental and modular planning 6) Assuring measurable milestones 7) Facilitating top management involvement
Function of Written Instructions
Function of Written Instructions: 1) Who does what (personnel with specific skill set) 2) How it is done (step by step)
Goal Statement
Goal Statement 1) Goals should be completed in 120-160 day period with a 50% reduction in the metrics selected.
If an operator is presented with a tray containing all parts to be used in product assembly, what does the tray represent?
If an operator is presented with a tray containing all parts to be used in product assembly, what does the tray represent? Visual Checklist
If the probability of a car starting on a cold morning is 0.6, and we have two such cars, what is the probability of at least on of the cars starting on a cold morning?
If the probability of a car starting on a cold morning is 0.6, and we have two such cars, what is the probability of at least on of the cars starting on a cold morning? (A ∪ B) = P (A) + P (B) - P ( A ∩ B) (A ∪ B) = 0.6 + 0.6 - (0.6 * 0.6) = 1.2 - 0.36= 0.84 Answer = 0.84
In Japanese based companies using TPM ....the goal for equipment break down losses is ________minutes
In Japanese based companies using TPM ....the goal for equipment break down losses is ________minutes Zero minutes
What is a method?
Method: An UNWRITTEN process that must be followed consistently---usually an internal procedure for a particular activity that is not required by any standard.
Problem Statement
Problem Statement 1) Details the issues that team aims to improve 2) Should include a baseline measure at the start of the project as well an anticipated completed date, 3) If the baseline measures differ from the team's assumptions, clarification is needed. or more data
Define Project Benchmarking
Project Benchmarking 1) Easier than many business processes, because of the opportunities for selection outside the groupof direct competitors. ----eg. new product introduction, construction, or new services. 2) Useful in selecting new techniques for planning, scheduling and controlling the project.
Relationship between Wiebull Distribution and Poisson Distribution
Relationship between Wiebull Distribution and Poisson Distribution When γ = 0, and β= 1, the Weibull distribution reduces to exponential distrituion with mean 1/ δ
Required Sample Size
Required Sample Size 1) Ideally, the alpha and beta error desired must be determined before the sample size is selected. 2) Sample Size needed depends on : a) Desired type I (a) or Type II (beta) risk b) Minimum value to be detected between the population means c) Variation in the characteristic being measured.
Look up the formal for proabability of B occurring given that event A has occurred
See primer
Team Leadership & Storming
Team Leadership & Storming---> Coaching Style 1) Continues close supervision with directive behavior 2) Supportive behavior 3) Increased listening to solicit feedback
The design of a control plan for a particular part incorporates information from a variety of sources such as flow charts, QFD, FMEAS, designed experiments and statistical studies. It is a tool to monitor and control the part of process. If used properly, the control plan avoids which of the following problems? a. becoming a substitute for written operator instructions b. having a listing of the critical Xs and Y's of the process c. Error proofing the process through various control plans d. being used as evidence of installed controls
The design of a control plan for a particular part incorporates information from a variety of sources such as flow charts, QFD, FMEAS, designed experiments and statistical studies. It is a tool to monitor and control the part of process. If used properly, the control plan avoids which of the following problems? a. becoming a substitute for written operator instructions b. having a listing of the critical Xs and Y's of the process c. Error proofing the process through various control plans d. being used as evidence of installed controls A= correct. B,C,D are examples of what a control plan should contain or exhibit. control plan should not be a substitute for detailed operator work instructions
What factors should be considered in order to determine sampling frequency?
What factors should be considered in order to determine sampling frequency? 1) Cost of Sampling 2) Losses associated with allowing the process to operate out of Control 3) Rate of Production 4) Probability with which various types of process shift occur.
What is the practical use of F-distribution?
What is the practical use of F-distribution? To study the equality of two variances
Which of following quality liminaries would be most clearly identified as a proponent of improvement and breakthrough projects? A. Ishikawa B. Deming C. Juran D. Crosby
Which of following quality luminaries would be most clearly identified as a proponent of improvement and breakthrough projects? A. Ishikawa B. Deming C. Juran D. Crosby C- Correct---Quality improvement phase would be considered a project approach to improvement Juran Trilogy has 3 processes---Quality planning, Quality control and quality improvement
Which of the distribution models events have 2 possibilities on each trial? a. normal b. poisson c. binomial d. Gamma
Which of the distribution models events have 2 possibilities on each trial? a. normal b. poisson c. binomial d. Gamma C- correct; Outcome from a Bernoullie trial has 2 possibilities, usually success or failure, as shown in bionomial distribution
Which of the following DOE strategies most resembles the Kaizen philosophy? a. Response surface b. Mixture designs c. EVOP d. One factor at a time analysis
Which of the following DOE strategies most resembles the Kaizen philosophy? a. Response surface b. Mixture designs c. EVOP d. One factor at a time analysis C= correct All 4 can be said to follow Kaizen. But EVOP is the only one that is a DOE strategy that most resembles Kaizen low risk, incremental, but continuous improvements philosophy.
When to use check sheet?
***When to use the check sheet:----> when the data can be observed and collected repeatedly by either the same person or the same location. It is also an effective tool when collecting data on frequency and identifying patterns of events, problems, defects, and defect location, and for identifying defect causes
Define these 3 types of variations?
1) Positional variation = Within part/ batch 2) Cyclical Variation = Part-to-part; batch-to-batch 3) Temporal Variation= Over time; Shift-to-shift
1,000 gamblers start rolling dice under the condition that if they roll 6 they can stay in the game. After 3 roles, how many gambler will stay?
1,000 gamblers start rolling dice under the condition that if they roll 6 they can stay in the game. After 3 roles, how many gambler will stay? Each roll of teh dice is mutually exclusive ecent with odds of 1/ 6. So after 3 rolls, the odd are : (1/6) (1/6) (1/6) = 1/ 216 Thus, 1000/ 216= 4.63 gamblers are left
10 traits of team members in Forming Stages
10 traits of team members in Forming Stages 1) Team getting to know each other 2) Pride in membership with the group 3) Trying to please team so tend to agree on initial discussions 4) "Honeymoon phase" and not much work accomplished.
Key points for checklist
2) Check List a) A tool used to ensure all important steps or actions have been taken b) Often a standard form is used c) Not one of the seven quality tools d) E.g.: All items in case cart are present before surgery in OR
3 Factors impact the evolution of team stages
3 Factors impact the evolution of team stages: 1) team leadership 2) Team maturity 3) Complexity of project (Scope /size)
Three Measures of Dispersion
3 Measures of Dispersion 1) Range 2) Standard Deviation 3) Variance
3 Methods to quantify measurement error in GR&R
3 Methods to quantify measurement error in GR&R 1) Range Method 2) Average & Range Method 3) ANOVA
3 Significance tests using interval data
3 Significance test using interval data 1) T-test 2) F-test 3) Correlation Analysis
3 Tools used in Enumerative (Descriptive) Studies
3 Tools used in Enumerative (Descriptive) Studies 1) Chi-square 2) Binomial distribution 3) Poisson distribution 4) Box plots
3 Types of sampling for SPC data collection
3 Types of sampling for SPC data collection 1) Random sampling = each part has equal chance being selected 2) Systematic sampling = sample every nth part 3) Subgroup sampling
3 assumption when 6sigma is the standard deviation due to measurement variability?
3 assumption when 6sigma is the standard deviation due to measurement variability? 1) Assume Measurement errors are independent, 2) Assume Measurement errors are normally distributed, 3) Assume Measurement errors are and independent of the magnitude of measurement
4 benefits of SIPOC
3 benefits of SIPOC 1) Display of cross functional activities in single, simple diagram 2) "Big picture" perspective to which additional detail can be added 3) Framework applicable to either large organizations or smaller projects. 4) Quickly familiarizes the team with the process at the organizational levels and project scope.
3 factors that influence to the sample size needed for hypothesis
3 factors that influence to the sample size needed for hypothesis: 1) Desired type I (alpha) and type II (Beta) risk 2) Minimum value to be detected between the population (u- u (0)) 3) Variation in the characteristics being measured (sigma)
3 reasons why management may get misleading information
3 reasons why management may get misleading information: 1) In vertical communication, subordinates may withhold or screen out negative information resulting in only positive to be reported. 2) Tendency to tell a supervisor, especially an authoritarian type, what he or she wants to hear, shielding the negative---> concealed errors and avoidable delays and costs. 3) Incumbent manager or leader is not always surrounded by allies---> competition and rivalry.
3 ways to construct Process Decision Program Chart
3 ways to construct Process Decision Program Chart: From the bottom level of some activity box, the PDPC adds levels for: a) identifying what can go wrong (failure mode or risks) b) consequences of that failure (effect or consequence) c) possible countermeasures (risk mitigation action plan)[1] 1) Graphic Method= shows the sequences required ---> Forward sequence (A1--> A2) 2) Modified tree diagram = shows the various points to considers through serious 'what if" conditions to find effect or consequence 3) outline format--> indicate the levels of problem.
3 ways to prove that project completed
3 ways to prove that project completed 1) Project charter 2) Analysis of Project measures 3) Internal Audit by Project sponsor
Calculating Process Capability (Pp)
3) Calculating Process Capability (Pp) Pp = (USL - LSL) / 6* s : where s the standard deviation, or the 'fatness' or dispersion of the bell curve. 4) What is a 'Good' Process Capability (Pp) Number?====> Six Sigma wants a Pp of above 1.5 because that would reflect a process with less than 3.4 DPMO - the definition of 6 Sigma quality.
4 Examples of Sources of Common Cause Variation
4 Examples Sources of Common Cause Variation 1) Method of sequencing in the process 2) Manufacturing equipment design 3) Nation variation in material supply 4) Measuring equipment design
4 Examples of Sources of Special Cause Variation
4 Examples of Sources of Special Cause Variation 1) Quality of incoming material 2) Operators with varying skills 3) Changes to process setting 4) Environmental variations
4 Methods used to identify customers?
4 Methods used to identify customers? 1) Brainstorming 2) SIPOC 3) Marketing analysis data 4) Tracking a product or service to delivery
4 Tools in Process Analysis and Documentation
4 Tools in Process Analysis and Documentation: 1) Flow charts 2) Process Maps 3) Written Procedures 4) Work Instructions
4 Types of Continuous Distributions:
4 Types of Continuous Distributions: 1) Normal distribution 2) Uniform distribution 3) Exponential distribution 4) Weibull distribution
4 tools used for risk analysis?
4 tools used for risk analysis? 1) risk priority number (RPN) 2) FMEA 3) Formula for expedited profit 4) SWOT
4 traits of team members in Performing Stages
4 traits of team members in Performing Stages 1) Team is effective, skill complement, synergy created 2) Team member realize interdependence 3) Develop ability to solve problem as a team 4) Large amount of work gets accomplished
6 Applications of Binomial distribution
5 Applications of Binomial distribution 1) Estimating the probabilities of an outcome in any set of success or failure trials 2) Sampling for attributes (acceptance sampling) 3) Number of defective items in a batch size of n 4) Number of items in a batch 5) Number of items demanded from an inventory 6) Model situation with only 2 outcomes
5 Benefits of using VOCS
5 Benefits of using VOCS (collection of customer needs and perceptions) 1) make decisions on products/services 2) Id. product features and specifications 3) Focus on improvement plan 4) Develop baseline metrics on customer satisfaction 5) ID customer satisfaction drivers.
5 Categories of Measurement Error
5 Categories of Measurement Error 1) Bias 2) Repeatability 3) Reproducibility 4) Stability 5) Linearity
5 Categories of Measurement System Errors
5 Categories of Measurement System Errors 1) Repeatability 2) Reproducibility 3) Bias 4) Stability 5) Linearity.
5 Reasons that Control Charts Popular
5 Reasons that Control Charts Popular 1) Improves productivity by reducing scrap and rework 2) Prevents defects ("Do it right first time") 3)Provides Diagnostic Information 4) Prevents Unnecessary Process Adjustments 5) Provides information about process capability.
5 Reasons why the Project Charter is Useful?
5 Reasons why the Project Charter is Useful? 1) Team is made aware of project goals & organization and operational boundaries ----->(prevents turf wars and draining energy) ------> Charter also eliminates confusion and defines the subject boundaries in the problem statement 2) Team will remain focused on original goals or the operating scope ----> It identifies areas that should not be addressed and identifies project deliverables 3) Team will work on projects that align with organizational goals- 4) Team champion will support the team goals---> Project charter documents top management's support and commitment. 5) Charter authorizes team to collect data and give access to resources.
5 Things that Project Statement must define
5 Things that Project Statement must define: 1) Objectives 2) Scope 3) Measures 4) Milestones 5) Resources
5 areas of risk for most projects>
5 areas of risk for most projects> 1) Technical Performance 2) Supportability risks 3) Cost risks 4) Schedule Risks 5) Environmental Risk
5 categories of risk for performance, cost, and schedules
5 categories of risk for performance, cost, and schedules 1) Technical performance 2) Supportability risk 3) Environmental risk 4) Cost risks 5) Schedule risks
5 elements of project charter
5 elements of project charter 1) Problem statement 2) Purpose 3) Benefits 4) Scope 5) Results
What are the 5 process performance measures?
5 process performance measures? 1) Defects per unit (DPU) 2) Defects per million opportunities (DPMO) 3) Rolled throughput yield (RTY) 4) Sigma levels 5)Process capability indices (PCI)
5 tools for capturing customer data?
5 tools for capturing customer data? 1) Voice of customer 2) Surveys 3) Quality function deployment 4) Interviews 5) Focus groups
5 traits of team members in norming Stages
5 traits of team members in norming Stages 1) Team members resolve their conflicts 2) Team members agree on mutually acceptable ideas to move forward 3) Start to function as a team 4) Being to trust and share ideas/work 5) Some work does get accomplished.
5 types of matrix diagrams
5 types of matrix diagrams: 1) L-type--L-shaped matrix relates two groups of items to each other (or one group to itself). 2) T-type--T-shaped matrix relates three groups of items: groups B and C are each related to A. Groups B and C are not related to each other. 3) X-type ---X-shaped matrix relates four groups of items. Each group is related to two others in a circular fashion. 4) Y-Type----Y-shaped matrix relates three groups of items. Each group is related to the other two in a circular fashion. 5) C-type ( 3D)----C-shaped matrix relates three groups of items all together simultaneously, in 3-D.
How do we determine what is a "good" process capability (Pp) number?
5) How do we determine what is a "good" process capability (Pp) number? Well, we want to have 6 sigmas (standard deviations) between the mean of the process and the LSL. Since a normal distribution is symmetric, that means we also want 6 sigmas between the mean and the USL. That's a total of 12 sigmas between the USL and LSL. In other words, USL - LSL should = 12 for us to reach 6 σ quality standards of 3.4 DPMO. See how that is reflected in the equation Pp = (USL - LSL) / 6* s ? Let's replace (USL - LSL) with 12: Pp = (USL - LSL) / 6* s = 12 σ / 6 * s = 2 σ / s
5 Advantages of Project Management:
6 Advantages of Project Management 1) Easy to use and low cost 2) Best for monitoring schedules and event timings 3) Hands-on feel of the project status 4) Customizable 5) Little training needed
6 Effects of negative team dynamics
6 Effects of negative team dynamics: 1) Cancelled projects 2) Missed deadlines or milestones 3) Ineffective resource utilization 4) Cost inefficiency/over-budget 5) Targets revised to team's advantage 6) Unmet goals /objectives for projects.
6 Measures based on project or organizational requirements
6 Measures based on project or organizational requirements: 1) Cost performance Index 2) Schedule performance index 3) Inquiry response time 4) Defect containment 5) Customer complaints or correction action requests 6)Defects per single one of code (SLOC) for software projects.
What 6 tools can be used to analyze customer data?
6 Tools can be used to analyze customer data? 1) Affinity diagram 2) FMEA 3) Pareto diagrams 4) Inter-relationship digraphs 5) Matrix Diagrams 6) Priority matrices
6 Tools for Problem-Solving
6 Tools for Problem-Solving: 1) PCDA/PDSA 2) 8D eight disciplines 3) FMEA/ FMECA 4) QFD 5) DOE 6)Hypothesis Testing *** Not competing techniques but are complementary to each other. **Standardized problem-solving methods result in uniform reporting of results.
6sigma is the standard deviation due to measurement variability and the assumptions are:
6sigma is the standard deviation due to measurement variability and the assumptions are: a) Measurement errors are independent b) Measurement errors are normally distributed c) Measurement error is independent of the magnitude of measurement.
7 Key Project Management Elements
7 Key Project Management Elements 1) ID schedule time limits 2) Allocation of functional responsibilities 3)Establishing continuous reporting methods 4) Selecting Applicable tradeoff methodologies 5) Measuring Accomplishments against plans 6) Identifying problems and applying corrective action 7) Improving capabilities for future project.
7 Tools of Statistical Process Control
7 Tools of Statistical Process Control 1) Histogram 2) Check Sheet 3) Pareto Chart 4) Cause and effect diagram 5) Defect concentration diagram 6) Scatter diagram 7) Control Chart
7 key tools for defining problem
7 key tools for defining problem 1) Affinity diagrams 2) interrelationship digraphs 3) tree diagrams 4) prioritization matrices 5) matrix diagrams 6) process decision program charts 7) activity network diagrams
5 traits of team members in Storming Stages
7 traits of team members in Storming Stages 1) Ideas voiced 2) Conflict of ideas & understanding --> reduced productivity 3) Risk of team getting stalled over conflicts 4) Necessary evil the team goes through to become a team. 5) Understanding of the scope and members' roles, responsibilities will be put to test.
8 Advantages of Computer/ Automated Project Management Methods
8 Advantages of Computer/ Automated Project Managment Methods: 1) Can model "what ifs" scenarios 2) Can show impact of alternate options 3) Diversity of formats/ detail of information presentation 4) Automatic scheduling and data collection 5) Real-time availability of variances in plan 6) Project status reports easily generated 7) Multi-location data input and information sharing 8) Easier summarization of project
8 Aspect of risk to consider
8 Aspect of risk to consider 1) Planned Schedule 2) Safety 3) Meeting established goals/objectives 4) Produceability 5) Serviceability 6) Reliability 7) Meeting customer expectations and requirements
8 Disadvantages of Computer/ Automated Project Managment Methods
8 Disadvantages of Computer/ Automated Project Management Methods 1) Learning curve for software user 2) Costly 3) Data entry & updates time-consuming 4) Computer's data inaccuracies lead to incorrect decisions 5) Manager's focusing on computer may lose sight of the project 6) Software options for specific projects not available 7) Limitation of environments for computer use 8) Unusual events or task relationships may not fit the software model
9 Disadvantages of Project Management
9 Disadvantages of Project Management 1) May not be portable depending on format 2) Only one site has project status information 3) Can't display large/ complex projects 4) Possible to overlook potential problem activities 5) Costs may not be tracked 6) Erasing status board--> permanent data loss. 7) To get interim status report, must be done manually 8) Difficulty doing project analysis 9) No flexibility if reporting format change or if new monitoring control identified.
A 3-prong 110 volt electrical plug is an example of: a. yin and yang balance of alternating current wires b. jidoka self-inspection process c. Heijunka design improvement and optimization d. poka-yoka permitting only proper plug insertion
A 3-prong 110 volt electrical plug is an example of: a. yin and yang balance of alternating current wires b. jidoka self-inspection process c. Heijunka design improvement and optimization d. poka-yoka permitting only proper plug insertion D= correct A 3-prong 110 volt electrical plug can only be inserted in the proper orientation with the hot, neutral and the gound connections properly connected to the corresponding terminatl in the electrical outlet.
A combined calculation of repeatability and reporducibility using the average and range method produces a ration of 7.42% of process tolerance. What ca be stated about the 7.2% value?
A combined calculation of repeatability and reporducibility using the average and range method produces a ration of 7.42% of process tolerance. What ca be stated about the 7.2% value? Answer= Measurement system is acceptable Acceptability criteria states that a combined R&R value: (1) less than 10% is considered acceptable. (2) Between 10% and 30% is considered marginal ( good but suitable to improvement) and (3) over 30% is not accepetable.
A comparison between Cp and Cpk for a process would find which of the following to be true? a. Cpk value is often larger than Cp b. Denominator of Cp calculation is half that of Cpk c. Cp value does not account for centering d. Neither calculation requires a sable process.
A comparison between Cp and Cpk for a process would find which of the following to be true? a. Cpk value is often larger than Cp b. Denominator of Cp calculation is half that of Cpk c. Cp value does not account for centering d. Neither calculation requires a sable process. C= correct Because Cpk corrects for centering, Cpk cannot be greater than Cp. Cp denominator is 6S and Cpk denominator is 3S
Confidence Intervals for Proportion
A confidence interval estimate for an attribute can be constructed to estimate the proportion of successes in a given category. Instead of using the sample mean to estimate the population mean, you use the sample proportion of successes (p): to estimate the population proportion (π). The sample statistic p follows a binomial distribution that can be approximated by the normal distribution for most studies. To demonstrate the confidence interval estimate of the proportion, you can examine the situation faced by the quality engineer for a large city newspaper. In the production of a newspaper, ... Many business decisions involve population proportions such as estimating market share and proportions of goods that are acceptable or defective.
A control chart for defect per unit uses probability limits corresponding to probabilities of 0.975 and 0.025. The central lime on the control chart is at 2.0. The limits vary with the value of n. What is the correct position of these upper and lower control limits when n=5?
A control chart for defect per unit uses probability limits corresponding to probabilities of 0.975 and 0.025. The central lime on the control chart is at 2.0. The limits vary with the value of n. What is the correct position of these upper and lower control limits when n=5? Question requires the calculation of u-chart control limits Note instaead of +/- sigma limits (99.7 % probability_ that +/- sigma limits apply Answer = 3.24 , 0.76 Equation UCLS = U-BAR +/- 1.96 (SQUARE ROOT OF U / SQUARE ROOT OF SAMPLE SIZE) UCL = 3 + 1.96 ( square root of 2 / square root of 5) = 3.24
A designed experiment of 3 factors (A, B, & C) at 2 levels was conducted. The 8 runs were analyzed, suggesting that one actor A showed significant improvement. the plan manager stated that no additional runs are needed. The best response:
A designed experiment of 3 factors (A, B, & C) at 2 levels was conducted. The 8 runs were analyzed, suggesting that one actor A showed significant improvement. the plan manager stated that no additional runs are needed. The best response: Additional replications are needed to verify the experiment. Experimental budgets should be sufficient to allow for additional runs
A fractional factorial experiment resulted in the main effects and two factor interactions effects being confounded. The confounding can be resolved how??
A fractional factorial experiment resulted in the main effects and two factor interactions effects being confounded. The confounding can be resolved how?? Answer: Run full factorial experiment with the same factors A resolution III experiment is a fractional factorial design in which no main effects are confounded with each other, but the main effects and 2 factor interaction effects are confounded. By running a full factorial experiment, the confounding can be resolved. Replicaitons of the trials will not remove the confounding of the main effects and the 2 factor interaction effects.
A gage should be sensitive enough to discriminate in measurement base don total tolerance speicification or process spread, whichever is smaller. What should the sensitivity be?
A gage should be sensitive enough to discriminate in measurement base don total tolerance speicification or process spread, whichever is smaller. What should the sensitivity be? Gage should be sensitive enough to detect differences in measurement as slight as 1/10 of the total tolerance specificaiton or spread, which ever is smaller
A lot of 50 pieces has 5 defectives. A sample of 2 is drawn without replacement. Probability that both will be defective is: ??
A lot of 50 pieces has 5 defectives. A sample of 2 is drawn without replacement. Probability that both will be defective is: ?? Answer= 0.0082 Use multiplicative law of probability: P ( A ∩ B) = P (A) * P (B) P ( A ∩ B) = (5/50) (4/ 49) = 0.0082
A lot of parts is found to be rejected and is 20% defective. What is the probability that the lot would have been accepted by the following sampling plan--when N= 10 and accept no defectives if the one or more defectives?
A lot of parts is found to be rejected and is 20% defective. What is the probability that the lot would have been accepted by the following sampling plan--when N= 10 and accept no defectives if the one or more defectives? 0.20= defects; 0.8 is no defects S= 10 Binomial Probability calculation Equation: ---- P(r) = C r= No. of defectives= 0 N= sample size = 10 P= proportion defective Solution = P(0) = 10!/ [0! (10-0)!] * (0.2 ^0) (1-02) ^ 10-0) P(0) = 0.1074 Section VII---14
A number resulting from manipulation of some raw data according to certain specified procedures is called?
A number resulting from manipulation of some raw data according to certain specified procedures is called? Statistic
A p-chart has been plotted for some time. Recently steps have been made to substaintially improve the process. One would not be surprised ot find that : ?/
A p-chart has been plotted for some time. Recently steps have been made to substaintially improve the process. One would not be surprised ot find that : ?/ Larer sample size mus be taken Hypothetical situation. Ofent with an improved process, a lartger sample size is required because a larger number of reading demonstrate zero defectives.
A process is in control with p-bar = 0.10 and n=100. The 3 sigma limits of the np control chart are ??
A process is in control with p-bar = 0.10 and n=100. The 3 sigma limits of the np control chart are ?? Answer is 1 and 19 UCL/ LCL = (n*p-bar) +/- 3* {square root of (n*p-bar (1-p-bar)} UCL = (0.1 *100) +/- 3* {square root of (100 *0.1 (1-0.1)} = (10) +/- 3* {square root of (100 *0.09)} = (10) +/- 3* {square root of (9)} = (10) + 3* {3} = 19 or 10 - 9 = 1
A process is producing material which is 20% defective. Five pieces are selected at random for inspection. What is the probability of exactly 3 good pieces being found in the samples?
A process is producing material which is 20% defective. Five pieces are selected at random for inspection. What is the probability of exactly 3 good pieces being found in the samples? Answer= 0.205 This is a binomial probability . n= samples; r= number of defectives ; p= proportional defective n! ______ (p ^x) (1-p) ^ n-x x! (n-x)! = 5! ___ (0.2 ^2) (1-0.2) ^ 5-2 2! (5-2) ! = [5*4/ 2] (0.04) (0.8 ^3) = 10 * 0.04 * 0.512 = 0.2048
A process shows lack of stability but yesterday's capability index was so great (1.77) that your supervisor decides to use it as a benchmark for all future process capabilities. What should your advise your supervisor?
A process shows lack of stability but yesterday's capability index was so great (1.77) that your supervisor decides to use it as a benchmark for all future process capabilities. What should your advise your supervisor? Answer= Don't use 1.77 value, first get the process to statistical stability. If the process shows a lack of stability, the process capability index is not valid. One should first get the process to statistical stability by eliminating special cause variation.
A product's USL = 7.3 lbs & LSL= 7 lbs. Actual data indicates that the product is currently running at an average of 7.465 lbs. with standard deviation of 0.03039 lbs. Calculations indicates Cp= 1.645 and Cpk=1.81. What conclusions can be made about the process. a. there is something wrong with the calcalations b. specifications are unrealistically set c. process is close to 6 sigma; negative Cpk is irrelevant d. Cp and Cpk values indicate that the proces is not centered.
A product's USL = 7.3 lbs & LSL= 7 lbs. Actual data indicates that the product is currently running at an average of 7.465 lbs. with standard deviation of 0.03039 lbs. Calculations indicates Cp= 1.645 and Cpk=1.81. What conclusions can be made about the process. a. there is something wrong with the calculations b. specifications are unrealistically set c. process is close to 6 sigma; negative Cpk is irrelevant d. Cp and Cpk values indicate that the process is not centered. D= correct. Negative Cpk is rate but possible. If the process is so out of center that all measures fall outside both limits, then one of the Cpk values must be negative Cp= (USL -LSL ) / 6 sigma Cp= (7.3 - 7) / (6 * 0.03039)= 1.645 Cpk= min [ (x-bar - LSL)/ (3 *sigma) , (USL - X-bar)/ (3 *sigma) Cpk = min [ 7.465 -7 / (3 * 0.03039) , (7.3 - 7.465/ (3 * 0.03039) = -1.81 Cp= 1.645 and Cpk= -1.81
A quality professional wants to chart the weight of packages on a highly automated food processing line. The recommended control chart is the X-bar-S chart and not the typical X-bar-R-chart, in wide use throughout the facility. What is the reason for this switch?
A quality professional wants to chart the weight of packages on a highly automated food processing line. The recommended control chart is the X-bar-S chart and not the typical X-bar-R-chart, in wide use throughout the facility. What is the reason for this switch? X-bar and S values will come automatically as a weight checker. The plot point and control limits will be proportional and is not a logical reason for making X-bar- S selection. The assumption must be the X-bar-S values can be supplied from an automated weight checker
A risk priority number indicates a more sever risk when it: A. It equals zero B. Value is lower C. Value is higher D. Value is indeterminate
A risk priority number indicates a more sever risk when it: A. It equals zero B. Value is lower C. Value is higher D. Value is indeterminate C- Correct
A scoop samples 100 units/ trial. What must be the average number of defects for there to be an 80% chance that more than one defect will be found in the sample?
A scoop samples 100 units/ trial. What must be the average number of defects for there to be an 80% chance that more than one defect will be found in the sample? Question requires the backward use of the Poisson table. Note that more than one defect is desired. For the sample to contain more than one defect with 80% probability, the table must be used to determine a 20% probability of 0 or 1 np= 3.0 Aswer= 3.0
A six sigma project has progressed ot the point that a control plan is required. Control plan activities can be considered closed after which of the following? a. process owner is named for the control plan b. responsible engineer is designated c. cross functional team signs off on the control plan d. control plan is a living document and is rarely closed.
A six sigma project has progressed ot the point that a control plan is required. Control plan activities can be considered closed after which of the following? a. process owner is named for the control plan b. responsible engineer is designated c. cross functional team signs off on the control plan d. control plan is a living document and is rarely closed. D= correct Control plan is considered a "living document" and is always subject to change. A, B, and C are partially correct. Yes the process owner is the preferred "owner of the control plan"
A stamping press makes 4 parts at a time. To set up control charting for this process, the best rational subgrouping should be to: a. separate control charts for each cavity, using 4 sequential part b. use one control chart for the press, using 4 parts from one stamping c. use one control chart for the press, using 4 sequential parts from one cavity d. use one control chart for the press, with a sample size of 9
A stamping press makes 4 parts at a time. To set up control charting for this process, the best rational subgrouping should be to: a. separate control charts for each cavity, using 4 sequential part b. use one control chart for the press, using 4 parts from one stamping c. use one control chart for the press, using 4 sequential parts from one cavity d. use one control chart for the press, with a sample size of 9 A= correct since each cavity may have different dimensions and wear, each cavity should be treated as a separate process. For example, three of the cavities may be producing parts in tolerance, while the 4th cavity is producing parts for specification
A team would be operating in which pahse of the Shewart cycle if they were conducting a pilot program test activity? A. Plan B. Act C. Check D. Do
A team would be operating in which phase of the Shewart cycle if they were conducting a pilot program test activity? A. Plan B. Act C. Check D. Do D= correct answer. )Section II-27-28 Studying the results of the pilot test to determine the next action would be in the Act phase. Carrying out the piolot detest of the idea is Do phase
A value stream map that describes the process after lean principles have been applied is called........???
A value stream map that describes the process after lean principles have been applied is called........??? Future State Map
ANOVA advantage over Average & Range Method
ANOVA advantage over Average & Range Method ANOVA can tell interactions (technician and parts) But also can tell variation due to process, repeatability, and reproducibility.
ASQ sectional history indicates 70% of all candidates successfully pass the CSSGB certification exam. A total of 12 company employees will take the upcoming CSSGB exam. Area manager promised a big bonus to all 12 people who pass the exam. What is the probability of getting the promised bonus?
ASQ sectional history indicates 70% of all candidates successfully pass the CSSGB certification exam. A total of 12 company employees will take the upcoming CSSGB exam. Area manager promised a big bonus to all 12 people who pass the exam. What is the probability of getting the promised bonus? Answer = 0.013841 Problem is clearly a bionomial situation. The probability of exactly 12 of all 12 CSSGB candidates passing the exam is given by the following formula, with n= 12, p-0.70, X=12 P (x= X) = [N! / X! (n-X!)] [p^x * (1-p) ^ n-X] P (x= 12) = [12! / 12! (12-12!)] [0.7^12 * (1-0.7) ^ 12-12 = 0.013841 The big bonus is very unlikely
ASQ sectional history indicates that 70% of all candidates successfully pass the CSSGB certification exam. A total of 12 company employees (including your) take the upcoming CSSGB exam. The area manager has promised a big bonus if all 12 you pass the exam. What is the probability of getting promised bonus.
ASQ sectional history indicates that 70% of all candidates successfully pass the CSSGB certification exam. A total of 12 company employees (including your) take the upcoming CSSGB exam. The area manager has promised a big bonus if all 12 you pass the exam. What is the probability of getting promised bonus. Answer = 0.013841 This is a binomial situation. The probability of exactly 12 of all 12 CSSGB candidates pass the exam is given by the following formula, with n=12, p=0.7, and x=12 P (x= X) = [n! / X (n- X)! ] * p^x * (1-p) ^ n-x P (x= 12) = [12! / 12 (12- 12! ] * 0.70^12 * (1-0.70) ^12-12 P (x= 12) = 0.013841 Big bonus unlikely
According to Cooper, which new product characteristic has lowest importance? a. attractive market b. unique and superior product c. being first to market d. good product launch
According to Cooper, which new product characteristic has lowest importance? a. attractive market b. unique and superior product c. being first to market d. good product launch C- correct (section III- 21/22)
According to Pande, which of the following is a legitimate reason for embracing a Six Sigma effort? A. The company currently has an effective improvement effort. B. Current changes are overwhelming the company resources C. Potential gains aren't sufficient to fund six sigma D. There are difficulties in meeting customer requirements
According to Pande, which of the following is a legitimate reason for embracing a Six Sigma effort? A. The company currently has an effective improvement effort. B. Current changes are overwhelming the company resources C. Potential gains aren't sufficient to fund six sigma D. There are difficulties in meeting customer requirements Answer= D Explanation = Pande suggest that answers A, B, and C are valid reasons to not undertake six sigma improvement Answer D is correct.
According to Womack, the most important LEAN principle is : A. Pursue Quality B. Make Value flow C. Pursue cost reduction D. Satisfy customers
According to Womack, the most important LEAN principle is : A. Pursue Quality B. Make Value flow C. Pursue cost reduction D. Satisfy customers B- Correct (seciton III; pg 2-3) ---> Womak and guiding principles of LEAN thinking
Accuracy
Accuracy 1) Unbiased true value and is reported as the difference between the average of a number of measurements and the true value.
Advancing order of attainment of benchmarks by Juran
Advancing order of attainment of benchmarks by Juran: 1) Customer Specification 2) Actual Customer Desire 3) Current Competition 4) Best in Related Industries 5) Best in the World.
Advantage of R& R range method compared to the average and range or ANOVA methods is that is is quick way to ____?
Advantage of R& R range method compared to the average and range or ANOVA methods is that is is quick way to ____? Quantify the total R &R portion of the measurment. Repeatability can only be qualified via ANOVA only.
Advantage of Stem-and-Leaf Plot over Histogram?
Advantage of Stem-and-Leaf Plot over Histogram? *** Stem-and-leaf permits data to be read directly fro he diagram, whereas, histogram may lose the individual data values as frequencies within the class intervals
Advantages of automated project management methods
Advantage of automated project management methods: 1) Can model what-if scenarios 2) Can show impact of alternate options 3) Multi-location user access 5) Real-time variances from plan 6) Easier to generate project status reports
Advantage of using ANOVA over average and range method for Gage R& R?
Advantage of using ANOVA over average and range method for Gage R& R? ANOVA can measure interactions. But both have the ability to partition variation into component parts
SIPOC-- Advantage
Advantage of using SIPOC 1) Display of cross-functional activities in single, simple diagram 2) "Big Picture" perspective to which additional detail can be added. 3) Framework applicable to either large organizations or smaller processes.
5 Advantages of PERT
Advantages of PERT 1) Planning required to identify the task information for the network and the critical path analysis can identify inter-relationships b/w tasks and problem areas. 2) Probability of achieving the project deadline can be determines, and by developing alternative plans, the likelihood of meeting the completion data is improved. 3) Changes in project can be evaluated to determine their effects. 4) large amount of project data can be organized and presented in a diagram for use in decision-making 5) PERT can be on unique, non-repetitive projects.
Advantages of Quality Cost System
Advantages of Quality Cost System 1) Manageable entity and single quality overview 2) Aligns quality with company goals 3) Provides problem prioritization system and a means of measuring change 4) Provides a ways to distribute controllable quality costs of maximum profit 5) Improves the effective use of resources 6) Provides emphasis for doing the job right every time 7) Establishes new product processes
Advantages of manual project management methods
Advantages of manual project management methods 1) Ease of use 2) low cost 3) Best for monitoring schedules and timing of events 4) Hands-on feel for project status 5) Customizable for specific project needs 6) Little training needed
Affinity Diagrams--3 uses
Affinity Diagrams 1) Good tool to take complex customer information and to organize it into logical categories. 2) This technique can be used to organize potential creative solutions 3) Best used in the "Problem Definition" stage of Six Sigma
Affinity Diagrams / KJ Method
Affinity Diagrams/ KJ Method 1) Techniques that individual/ team can use for problem-solving, especially for new or complex problems 2) Similar to mind-mapping in that it generates ideas that link with other ideas. 3) Can be used int he planning states of a problem to organize ideas and information.
After a screening experiment , all significant factor happen to be qualitative. A decision to run some intermediate values will result in : a. nothing, it is not possible to optimize qualitative variables b. discovery of the optimum combination qualitative variables c. Indication fo curvature around the zero setting. d. discovery of potential interactions between the qualitative variables
After a screening experiment , all significant factor happen to be qualitative. A decision to run some intermediate values will result in : a. nothing, it is not possible to optimize qualitative variables b. discovery of the optimum combination qualitative variables c. Indication fo curvature around the zero setting. d. discovery of potential interactions between the qualitative variables C= correct Only quantitative factors can be optimized through a surface response experiment. There is no middle point, or zero, in a qualitative factor. For example, if one is studying the variable machine, with machine 1 as the low and machine 2 as the high, even if the machine influence is a significant factor in the model, thee is no machine 1-1/2 to study. therefore, it is impossible to optimize qualitative variables qualitative variables
After attending SPC classes, a second shift production supervisor implements a mean chart for an important quality characteristic. The supervisor said " I'm happy to annouce that out of 24 samples means (sample size 5 units, taken every 20 minutes) none were found outside of the specification limits. The process is running falwlessly. What can be stated about the supervisor's conclusion> a. supervisor is wrong, there is no measure of the confidence level b. supervisor is wrong, two different populations are being compared. c. supervisor is right, for the wrong reasons d. supervisor is right, all values are within specifications.
After attending SPC classes, a second shift production supervisor implements a mean chart for an important quality characteristic. The supervisor said " I'm happy to annouce that out of 24 samples means (sample size 5 units, taken every 20 minutes) none were found outside of the specification limits. The process is running falwlessly. What can be stated about the supervisor's conclusion> a. supervisor is wrong, there is no measure of the confidence level b. supervisor is wrong, two different populations are being compared. c. supervisor is right, for the wrong reasons d. supervisor is right, all values are within specifications. B= correct The world of the sample means and the world of individual values are completely different. Only individual values can be compared with specifications. Sample means will concentrate closer to the center. The relationship between 2 population spreads is given by the formula: Sigma (x-bar) = Sigma (x) / Square root of N samples
After attending SPC classes, a second shift production supervisor implements a mean chart of an important quality characteristics. Superviors says " I'm happy to announce that out of 24 samples (sample size 5 units taken every 20 minutes) now were outside the specification limits. Conclusion?
After attending SPC classes, a second shift production supervisor implements a mean chart of an important quality characteristics. Superviors says " I'm happy to announce that out of 24 samples (sample size 5 units taken every 20 minutes) now were outside the specification limits. Conclusion? Supervisor are wrong, two different populations are being compared World of sample means and work of individual values are completely different. Only individual values can be compared with specifications. Sample means will concentrate closer to the center. Relationship between two population Sigma (X-bar ) = Sigma (X) / (Square root of sample size)
After the development of a viable corporate strategy, the next logical step would be: A. PDCA B. Deployment C.SWOT D. Benchmarking
After the development of a viable corporate strategy, the next logical step would be: A. PDCA B. Deployment C.SWOT D. Benchmarking B-correct---SWOT and benchmarking occurs before strategy development. PDCA is problem solving tool that is off target with direction . Deployment is after the strategy development
All of the factors that might be contributing to a production problem must be discovered. Which of the following problem-solving tools would be the best selection? a. Pareto diagram b. fishbone c. histogram d. control chart
All of the factors that might be contributing to a production problem must be discovered. Which of the following problem-solving tools would be the best selection? a. Pareto diagram b. fishbone c. histogram d. control chart B= correct
Almost in every definition of the standard work, one would find some combination of ?
Almost in every definition of the standard work, one would find some combination of ? Answer = materials, man (workers) , and machinery
American visitors to an aluminum plant in Japan were given white gloves to wear. What category of 5S is this an example of? a. Sort b. Scrub c. Straighten d. Standardize
American visitors to an aluminum plant in Japan were given white gloves to wear. What category of 5S is this an example of? a. Sort b. Scrub c. Straighten d. Standardize B= correct--white rage inspection
An X-bar and R-chart can be helpful in controlling a process when: a. machine capability is wider than the specification b. it is necessary to know when to investigate a process for causes of variation c. reduced sample size is needed d. acceptable quality level must be established
An X-bar and R-chart can be helpful in controlling a process when: a. machine capability is wider than the specification b. it is necessary to know when to investigate a process for causes of variation c. reduced sample size is needed d. acceptable quality level must be established B= correct. Reducing sample size and establishing acceptable quality levels relate to sampling plans. (A) untrue
An X-bar control chart is based on a sample size of 4. What happens if an operator mistakenly plots the value of the single observation on the control chart? a. will not cause any mis-judgments if the process is in control. b. will always be plotted near the center line of the control chart c. will cause the associated R chart to show an out of control condition d. Increases the probability of the process being labeled out of control
An X-bar control chart is based on a sample size of 4. What happens if an operator mistakenly plots the value of the single observation on the control chart? a. will not cause any misjudgments if the process is in control. b. will always be plotted near the center line of the control chart c. will cause the associated R chart to show an out of control condition d. Increases the probability of the process being labeled out of control D= correct. The standard deviation of the sample mean of 4 is one-half the standard deviation of the individuals. This is because the standard deviation of the sampling distribution is inversely proportional to the square root of the sample size. In this case, square root of 4 is 2. Since the standard deviation of individual measurement is twice that of the average of the sample of 4, the corresponding limits on an X-bar control chart would be twice as wide as those for the average from a sample of 4 points. Thus, plotting a single observation increases the probability of the point falling outside the control limits when the process is in control.
An X-bar-R chart has been in control for long time. Points for the last 50 samples are very near the center line on the chart. In fact, they are all within one sigma of the center line. This indicates what? a. desirable situation b. undesirable situation c. Process standard deviation decreased during the last 50 samples d. Control limits are incorrectly computed
An X-bar-R chart has been in control for long time. Points for the last 50 samples are very near the center line on the chart. In fact, they are all within one sigma of the center line. This indicates what? a. desirable situation b. undesirable situation c. Process standard deviation decreased during the last 50 samples d. Control limits are incorrectly computed C= correct
An X-bar-R chart has been in control for some time. If the range suddenly and significantly increases, what happens to the mean?
An X-bar-R chart has been in control for some time. If the range suddenly and significantly increases, what happens to the mean? Answer= Mean occasionally show out of control of either limit If the range significantly increases, the more spread of the individual reading is occurs. Mean will not always increase or decrease. Mean will not always stay the same.
An advantage of training managers in six sigma concepts before improvement team member is ? A. Managers have more time available for training B. Managers must lead the deployment of six sigma C. Managers must understand the concepts better than the team member D. Manager must pay for worker training
An advantage of training managers in six sigma concepts before improvement team member is ? A. Managers have more time available for training B. Managers must lead the deployment of six sigma C. Managers must understand the concepts better than the team member D. Manager must pay for worker training B-correct
An attempt to minimize the impact of human error in a process is called" a. Poke-yoke b. Jidohka c. Kaizen D. Muda
An attempt to minimize the impact of human error in a process is called" a. Poke-yoke b. Jidohka c. Kaizen D. Muda A- correct. (B= visual board)
An improvement team has completed several RPN values and is not ready to institute improvements. There are 3 failure modes with the same RPN score in the table below. First line time which should be reduced would be? Bad battery---Severity-9;Occurrence= 7; Detection =5 ; RPN= 315 Cracked welds ---Severity-7; Occurrence= 9; Detection =5 ; RPN= 315 Missing bolts------Severity-5 Occurrence= 7; Detection =9 ; RPN= 315 a. Bad battery b/c highest severity rating b. Cracked weld b/c highest occurrence c. Missing bolts because highest detection level d. Rankinga re the same, so choose any one to start
An improvement team has completed several RPN values and is not ready to institute improvements. There are 3 failure modes with the same RPN score in the table below. First line time which should be reduced would be? Bad battery---Severity-9;Occurrence= 7; Detection =5 ; RPN= 315 Cracked welds ---Severity-7; Occurrence= 9; Detection =5 ; RPN= 315 Missing bolts------Severity-5 Occurrence= 7; Detection =9 ; RPN= 315 a. Bad battery b/c highest severity rating b. Cracked weld b/c highest occurrence c. Missing bolts because highest detection level d. Ranking are the same, so choose any one to start A- correct
An organization is considering a kaizen blitz event fro improving the system software functionality by replacing the network server and implementing a new software program. Which of the following is the best response? a. this is an ideal application because the project would only take 3-5 days b. A minimum of 25 people should be involved because of the short duration of change. c. This is not a suitable application because of the complexity and duration d. This change-over should be done on the weekend to avoid downtime
An organization is considering a kaizen blitz event fro improving the system software functionality by replacing the network server and implementing a new software program. Which of the following is the best response? a. this is an ideal application because the project would only take 3-5 days b. A minimum of 25 people should be involved because of the short duration of change. c. This is not a suitable application because of the complexity and duration d. This change-over should be done on the weekend to avoid downtime C= correct. Kaizen blitz event are suitable for projects which can be implemented in 1-5 days, are specific to a single department or area, and do not require long lead times or long-term planning.
An understanding of variation categories is important in the selection of rational subgroups for control charting and other purposes. Which of the following would be difficult variation source to reduce by control charting and subsequent floor level follow-up action? a. time-to-time variation b. stream-to-stream variation c. inherent process variation d. piece positional variation.
An understanding of variation categories is important in the selection of rational subgroups for control charting and other purposes. Which of the following would be difficult variation source to reduce by control charting and subsequent floor level follow-up action? a. time-to-time variation b. stream-to-stream variation c. inherent process variation d. piece positional variation. C= Correct. Inherent process variation often requires total system change which is outside the scope of floor level personnel
Analysis of risk involves two measures of failures. These measures are: A. Failure analysis and failure effects B. Failure mode and failure methods C. Failure severity and failure probability D. Failure mechanism and failure mode
Analysis of risk involves two measures of failures. These measures are: A. Failure analysis and failure effects B. Failure mode and failure methods C. Failure severity and failure probability D. Failure mechanism and failure mode
Analysis of risk involves two measures of failures. These measures are: A. Failure analysis and failure effects B. Failure mode and failure methods C. Failure severity and failure probability D. Failure mechanism and failure mode
Analysis of risk involves two measures of failures. These measures are: A. Failure analysis and failure effects B. Failure mode and failure methods C. Failure severity and failure probability D. Failure mechanism and failure mode C- Correct
Analytical (inferential) Statistics
Analytical (inferential) Statistics: 1) Uses data from a sample to make estimates or inferences about the population from which the same was drawn
Analyzing Process Capability
Analyzing Process Capability 1) Predictable pattern of statistically stable behavior where the chance causes of variation are compared with engineering specifications---esp. to judge the suitability of the process 2) Capable Process-------->Bell-shaped spread that is narrower than the tolerance range. 3) Three steps in process capability study: a) Planning for Data Collection b) Collecting Data c) Plotting and analyzing data
Application of Lognormal Distribution
Application include simulations of: 1) Distribution of wealth 2) Machine downtimes 3)Duration of time 4) Phenomenon that has a positive skew (tails to the right)
Application of Nelson Funnel
Application of Nelson Funnel Applied to tampering and common kneejerk reactions on the part of management, all of which are impediments to effective management and continual improvement, including: 1) Adjusting a process when a part is out of specifications 2) Making changes without the aid of control charts 3) Changing company policy based on the latest attitude survey 4) Modifying the quota to reflect current output 5) Using variances to set budgets 6) Relying on history passed down from generation to generation
Application of Process Capability Studies
Application of Process Capability Studies 1) Evaluation of new equipment 2) Reviewing tolerance based on inherent variability of a process 3) Assigning equipment to product 4) Routine process performance audits 5) Effects of adjustments during processing
Application of Process Decision Program Charts
Application of Process Decision Program Charts a) New/ Unique/ complex Problems or those with sequence of difficult and challenging steps b) Can be used to create contingencies and counter problems available to the team
Application of Scatter Diagram
Application of Scatter Diagram 1) Root cause analysis 2) Estimation of correlation 3) Making prediction using a regression-line fitted to the data.
Application of multi-variant studies
Application of multi-variant studies 1) Minimizes variation by identifying areas in which excess variation and less variation. 2) Investigation of stability or consistency of a process. 3) Determination of where the variability is coming from within the process.
4 Applications of probabilistic assessments
Application of probabilistic assessments of: 1) Mean time between failure (MTBF) 2) Arrival times 3) Time, distance or space between occurrences of the events of interest 4) Queuing or wait-line theories
Appraisal Cost Examples
Appraisal Cost Examples 1) Inspections of Prototype, shipping& receiving 2) Test Equipment maintenance 3) In-process inspections 4) Equipment Calibrations 5) Expense Reviews 6) Lab testing
Costs associated with measuring, evaluating, or auditing products/services to ensure conformance to quality standards and performance requirements
Appraisal Costs Costs associated with measuring, evaluating, or auditing products/services to ensure conformance to quality standards and performance requirements
Appropriate situational Communications
Appropriate Situational Communications 1) Reprimanding employee done privately and verbally 2) Documented letter for repeated offenses 3) Business agreements may be verbally but followed by a letter to ensure that both parties have the same understanding. 4) Strategic initiaitves, such as six sigma should be communicated by the CEO.
Which Measurement Scale? Central Location is Arithmetic Mean
Arithmetic Mean Central Location is Arithmetic Mean
As a good experimenter, you have built a predictive model of the experimental data. The differences between the actual response data and the model data are called???
As a good experimenter, you have built a predictive model of the experimental data. The differences between the actual response data and the model data are called??? Residuals Look up the definitions for: Nested experiment, efficeincy of estimators
As a new green belt in the company, you are given the following data: X-double bar = 4.241 mm, S- x bar = 0.565mm, n=5 You decide to estimate the process parameters but discover that the original data was lost and all you have are these 3 numbers. What is the best estimate that can be made of the process parameter under the current circumstances?
As a new green belt in the company, you are given the following data: X-double bar = 4.241 mm, S- x bar = 0.565mm, n=5 You decide to estimate the process parameters but discover that the original data was lost and all you have are these 3 numbers. What is the best estimate that can be made of the process parameter under the current circumstances? Answer= X-double = 4.241 and Sigma (x-bar)= 1.263 The information given refers the average and standard error of the mean for sample size. Using the central limit theorem, an estimate can be made for the population parameters as follows: Sigma (x- double bar) = Sigma (x-bar) * Square root of sample size = 0.565 * Square root of 5 = 1.263
As with the 7 quality management tool, the Japanese concept of workplace organizations, 5S, has been Americanized. Which of the 5 is the hardest to find in the American system? a. Seiri b. Seiton c. Shitsuke d. Sieso
As with the 7 quality management tool, the Japanese concept of workplace organizations, 5S, has been Americanized. Which of the 5 is the hardest to find in the American system? a. Seiri b. Seiton c. Shitsuke d. Sieso C= correct There are several version of the American 5S system. they can include sort, straighten, scrub, shine, systematize, and safety. Items in the American system seen to be directed mainly at the system with implications for responsibility of the operator. Shitsuke = personal cleanliess
Assume in a R & R study, using the ANOVA method, that the technician - to - technician error was noted to be very low. this value is defined as?
Assume in a R & R study, using the ANOVA method, that the technician - to - technician error was noted to be very low. this value is defined as? Reproducibility error = answer
Assuming no interactions, the main effects of analysis of one-half factional factorial experiment compared with a comparable full factorial experiment, produces which outcome: a. Both results are approximately the same b. only full factorial is accurate c. Both can be calculated but computer software is required. d.one-half factional factorial gives one-half of the final outcome
Assuming no interactions, the main effects of analysis of one-half factional factorial experiment compared with a comparable full factorial experiment, produces which outcome: a. Both results are approximately the same b. only full factorial is accurate c. Both can be calculated but computer software is required. d.one-half factional factorial gives one-half of the final outcome A= answer. D= the worst possible choice
Assuming that repeatability and reporducibility variance are known from R & R study, what can be determined?
Assuming that repeatability and reporducibility variance are known from R & R study, what can be determined? Measurement variation By taking the square root of the combined variances, the standard deviation can also be found. Not enough information to find the total or partial variation.
At the early stages of DMAIC project, the voice of the customer shouted "safety" in every customer focus groups, customer interview, and customer survey. The control plan in now missing the team member list. The control also addresses product performance in detail, but not product safety. Can this control plan be implemented?
At the early stages of DMAIC project, the voice of the customer shouted "safety" in every customer focus groups, customer interview, and customer survey. The control plan in now missing the team member list. The control also addresses product performance in detail, but not product safety. Can this control plan be implemented? No, the main CTQ requirement was not addressed in the control plan
At what 5S step would standards for each of the 5 steps be established?
At what 5S step would standards for each of the 5 steps be established? Sustain = answer
At what stage in the 5S program would visual controls be employed?
At what stage in the 5S program would visual controls be employed? Step 4: Standardize
Attribute Data/ Discrete
Attribute Data 1) Data values can only be integers--eg. No. of defects, absent people, kind of perfomance.
Average & Range Method Application
Average & Range Method 1) Determine repeatability by examining variation between individual appraisers and within their measurement reading 2) Determine reproducibility by examining variation between the average of individual appraisers for all parts measured 3) Establish process variation by checking the variation between part averages that are averaged among technicians
Average Run Length
Average Run Length Average number of points that must be plotted on control chart before a point indicates an out-of-control conditions. ARL = 1/ (p)
Average Standard Deviation Chart Application
Average Standard Deviation Chart Application 1) Subgroups greater than 10 2) Less sensitive to detecting shirt 3) Provides Economic balance between the cost of running SPC and information that can be usefully derived.
Average and Range Method
Average and Range Method Total measurement system variability that allows for separation into repeatability, reproducibility and part variation
Average and Range Method and ANOVA R & R Method
Average and Range Method and ANOVA R & R Method
Based on the definition of upper and lower control limits, how often should one expect a normally distributed in control proess to plot outside the control limits?
Based on the definition of upper and lower control limits, how often should one expect a normally distributed in control proess to plot outside the control limits? Answer= 27 / 10,000 points the upper and lower control limits represent 3 standard deviations from the mean. Normally distributed process about the mean will have 99.73% of its expected calues fall with 3 SD (the control limits) That is, 9,973 out of 10,000 points. By subtraction, one finds that this process expects 27 out of 10,000 If control limits set to 2 standard deviation, then you have 456 out 10,000 point that fall outside the control limts
Based on the large number of variables under study, an engineer is considering a fractional factorial instead of a full factorial to analyze a process. Apart from the possibility of studying a large number of factors with relatively few experiments, what other characteristic will support a decision to use fractional factorial instead? a. Suspecting that there are many interactions b. process is well known and the only main factors are of concern c. fractional factorial will determine the main effect curvature d. blocking is needed to account for nuisance factors in the study.
Based on the large number of variables under study, an engineer is considering a fractional factorial instead of a full factorial to analyze a process. Apart from the possibility of studying a large number of factors with relatively few experiments, what other characteristic will support a decision to use fractional factorial instead? a. Suspecting that there are many interactions b. process is well known and the only main factors are of concern c. fractional factorial will determine the main effect curvature d. blocking is needed to account for nuisance factors in the study. B= correct (A) and (C) are conceptually wrong. (B ) and (D) are valid concepts but only B answers the question.
Batch with 2% defectives. N= 30 and batch accepted if 1 or less defects found. What is the probability that batch is rejected?
Batch with 2% defectives. N= 30 and batch accepted if 1 or less defects found. What is the probability that batch is rejected? Approximate using Poisson Table. ---> (np= 0.6) and it can been seen that probability of getting 1 or fewer defects si 0.878. thus the probability of rejecting the lot = 1- 0.878 = 0.122 or 12.2%
Define Benchmarking
Benchmarking Process of comparing the current project methods or processes with the best practices and using this information to drive improvemnet of all company performance. Standard for comparison may be a competitor within the industry (usually in an unrelated business segments)
Benchmarking Companies compare their own performance against 4 things
Benchmarking Companies compare their own performance against 4 things: 1) Best in class company performance 2) Companies recognized as industry leaders 3) Company's toughest competitors 4) Any known process that is superior to the company's
Benchmarking Sequences
Benchmarking Sequences 1) Determine Current Practice ---> Select problem area, Id. key performance factors, understand your own and others' processes, select performance criterial based on needs and priorities. 2) Id. Best Practices ----> Measure performance in the organization. find internal and external organization to benchmark, determine the leader in each criteria area 3) Analyze Best Practices -----> Visit the benchmark partner to collect data & info than evaluate/ compare current practices with benchmark 4) Model Best Practices ---> Drive improvement changes to advance current performance levels, extend performance breakthroughs within the organization, incorporate new information in decision-making, and share results with benchmark partner.
5 ways that Benchmarking is a Continuous Improvement Process
Benchmarking as a Continuous Improvement Process: 1) Measures the most relevant, specific attributes of its own products/services/ practices/ stratgies 2) Uses information to improve its own performance 2) Determines how those companies achieved their superior performance 3) Aims to perform at the level of the benchmarked process 4) Continuosly repeats itself
Benefits of Initial Project
Benefits of Initial Project 1) Team members learn about team work 2) Organization achieves its objectives 3) Individuals gain experience in project selection and completion 4) Project that is selected may solve a problem ---> eg. cost reduction, reduced cycle time, or efficient use of resources. 5) Scope of project can vary and can even be extended to many years.
What are the benefits of balanced scorecard?
Benefits of balanced scorecard? 1) Provides approach to measuring multiple aspects of business 2) Financial aspect of business is limited to past events but balanced scorecard gives 4 perspectives on business performance (financial, customer, internal processes, and learning/growth) 3) Helps organization align vision and goals with the objective of ensuring that no single area far outweighs the others---gives balanced method of measuring results.
Best approach to identifying the key characteristics that require SPC monitoring
Best approach to identifying the key characteristics that require SPC monitoring 1) SPC monitoring is expensive so need to carefully select process parameters and characteristics 2) To identify these parameters requiring process control -----> FMEA + Control plan + SPC planning
Best measurement of project's activity?
Best measurement of project's activity? 1) Project Time Line-= most visible yardstick of measurement of project activities 2) Quality Perspective----> both early & late projects have the opportunity for poor quality compared to on-time projects. ----> Early then possible corner-cutting and if late, then what errors created the delay.
Best-Fitting Line in Simple Regression
Best-Fitting Line in Simple Regression: 1) Best-fitting line does fine the line that best fits the sample data 2) If the sample is randomly chosen, that line should be close to the line that best fits the population data.
Bias
Bias 1) Difference between output of measurement system and true value------->Lack of bias= Accuracy 2)**Know the formula for Bias 3) Bias is reported as a percent of process variation or percent of tolerance.-----> Negative bias (underestimated value); Positive bias (over-estimated bias) 4) Statistical significance of bias is tested using the t-distribution-----> increase the number of measurements increases the discriminatory power of the t-test.
Binomial Distribution
Binomial Distribution 1) Process that consists of a sequence of N independent trials, where the outcome of each trial is either a "success" or "failure".---"Bernoulli trials" 2) If the probability of "success" on any trial (p) is constant, then the number of successes has a binomial distribution. 3) Binomial distribution is good for sampling infinatetly large population where p represents the fraction of defective or non-conforming items in the population
Binomial Distribution
Binomial Distribution Basic assumptions: Discrete distribution Number of trials are fixed in advance Just two outcomes for each trial Trials are independent All trials have the same probability of occurrence
Binomial distribution is a discrete distribution and may be used to describe: a. sampling without replacement from finite population b. case of n independent trails with probabilities constant from trial-to-trial c. case of n independent trials with several outcomes for each trial d. Sampling without replacement where there are several potential outcomes
Binomial distribution is a discrete distribution and may be used to describe: a. sampling without replacement from finite population b. case of n independent trails with probabilities constant from trial-to-trial c. case of n independent trials with several outcomes for each trial d. Sampling without replacement where there are several potential outcomes B= correct; Hypergeometric distribution--"without replacement" and "finite population"
How are Cpk and Ppk alike?
Both Cpk and Ppk relate the standard deviation and centering of the process about the midpoint to the allowable tolerance specifications. An estimate for Cpk = Cp(1-k). and since the maximum value for k is 1.0, then the value for Cpk is always equal to or less than Cp. Cpk will never exceed the Cp. Similar to Ppk, the Cpk capability index is only a function of the standard deviation and mean of the data, not a nominal (target) value that may be historical or provided by the customer. The Cpm capability calculation accounts for a nominal value.
Box -and- whisker plot---> Purpose & Application
Box -and- whisker plot 1) Purpose= pictorial view of minimum, maximum, median, and interquartile range in one graph 2) Application= Provides more information than distribution plot but easier to interpret. Outliners are easily identified on the graph.
Box Plot
Box Plot 1) Displays 3 quartiles, the minimum, and the maximum of the data on a rectangular box 2) Box encloses the inter-quartile range with the lower line at the 1st quartile (Q1) and the upper lines at the Q3 2) Median is represented by the line drawn through the box at Q2 3) Whiskers = line at either end that extends tot he extreme values
Box has 27 black and 3 red balls. What is the probability that the ball is picked is red?
Box has 27 black and 3 red balls. What is the probability that the ball is picked is red? Black = 27/ 30=0.9 Red= 3/ 30 = 0.1 Answer = 0.1000
Box- and -Whisker Plots (Box Plots)
Box- and -Whisker Plots (Box Plots) ---John W. Tukey 1) Most simple and useful way to summarize data-----> 5 number summary of the data with a central line representing the median 2) Upper and lower quartiles of the data define the end of the box ---------> min and max data points are the end of the line "whiskers" 3) Notch Widths are calculated so that if 2 median notches do not overlap------->means are different with 5% significance. 4) Variable width notches are proportional to the log of the sample size. 5) Outliners (Asterricks)------Points that are more than 1.5 times the inter-quartile distance from each quartile.
Business Case (Financial Impact) Section of the Project Charter
Business Case (Financial Impact) Section of the Project Charter 1) Summarizes the strategic reasons of the project---generally about quality, cost, or deliver of product with financial justification 2) Basic Activities a) Design a new product /process b) Redesign new process / existing process
Business Process VS. Organization Function
Business Process VS. Organization Function: 1) BPM addresses the problem of unclear functional relationships leading to failure of business processes by applying a project management and matrix organization approach to production 2) Derived from Military/ Industry Sector 3) May rely on intentional sub-optimiztion of a local function to improve overall business outcome 4) Six Sigma black belt role is to service as project management for overall business improvement projects----> a) Bridge the gaps b) Eliminate Confusion c) Identify global business improvement opportunities verse local functional ones.
C-chart
C-chart 1) Attribute Control Chart for NUMBER of non-conforming defects.
CPK & Short-term Capability
CPK & Short-term Capability: Generally, a CPK greater than 1.33 indicates that a process or characteristic is capable in the short term. Values less than 1.33 tell you that the variation is either too wide compared to the specification or that the location of the variation is offset from the center of the specification. It may be a combination of both width and location.
CPM Cost & Time Trade off
CPM Cost & Time Trade off 1) Crashing activities beyond a certain activity (eg activity I) may increase cost without further reduction in time----> leading to useless waste in resources. 2) Assumption made in crashing an activity is that it is independent of other activities
CTQ Tree
CTQ Tree 1) Translates the initial customer requirements to numerical or quantified requirements for the product/service---- 2) begins with a general requirement to the specific and will require 2 or 3 levels to transgress from need---> Drivers ---> CTQ ***Exact metrics are not determined at this stage.
Calculate standard deviation of the population for the 5 samples: 1.5, 1.2, 11.1 1.0. 1.6
Calculate standard deviation of the population for the 5 samples: 1.5, 1.2, 11.1 1.0. 1.6 Answer= 0.259
Calculate takt time per system data provided: Demand= 30 units/ hour Step 1 @ 20 units/hr Step 2 @ 40 Step 3 @ 12 Step 4@ 16 Step 5@20 A. 5 min B. 1.8 min C. 3 min D. 2 min
Calculate takt time per system data provided: Demand= 30 units/ hour Step 1 @ 20 units/hr Step 2 @ 40 Step 3 @ 12 Step 4@ 16 Step 5@20 A. 5 min B. 1.8 min C. 3 min D. 2 min Step 2= bottleneck Takt time= 2 min --D Takt = Net operating time per period / customer demand Net operating Time= 60 min per hour Customer demand = 30 unit/ hour
Calculate the performance ration for the process with spread of 20-30 and lower and upper specification limits of 15 and 35 respectively.
Calculate the performance ration for the process with spread of 20-30 and lower and upper specification limits of 15 and 35 respectively. P(R)= 6 sigma / (USL -LSL) P(R)= 10 / (35 -15) = 10/20 = 0.5
Calculation of reproducibility results in value of zero while repeatability yeilds a positive number. Conclusion?
Calculation of reproducibility results in value of zero while repeatability yeilds a positive number. Conclusion? Reproducibility =0 means operator has no effect on the measurement --aka no appraiser effect
Calculation of reproducibility using the average and range method comes from ???
Calculation of reproducibility using the average and range method comes from ??? Examining the variation between the average of the appraisers for all parts measured Reproducibility is commonly referred to as "between appraisers" variability. Measuring the variation between the average of the appraisers for all parts measured will give an assessment of the reproducibility
Calibration of measuring instruments is necessary to maintain accuracy. How does calibration affect precision?
Calibration of measuring instruments is necessary to maintain accuracy. How does calibration affect precision? Calibration has minimum impact on precision.
Process Specifications: Can A Process Meet Specifications?
Can A Process Meet Specifications? The answer is in the amount of variation in your process. If your process spread is greater than the specification spread, then the answer is no. However, if the process spread is less than the specification spread, then process variation is low enough for it to fit.
Causes of Feuding
Causes of Feuding 1) Conflict resolution not handled effectively by team leadership 2) Lack of mutual respect between team members 2) Team operating ground rules not enforced
Causes of Floundering team member
Causes of Floundering team member: 1) lack of team direction---> due to (a) High-profile leaders that don't attend meetings or (b) Major organizations Changes 2) Overwhelmed team members---> due major changes (1) leadership (2) downsizing (3) mergers (4) offshore transfers 3) Postponed team decision ---> No direction from leadership
Causes of Non-linearity in Gauge R& R
Causes of Non-linearity in Gauge R& R 1) Improperly calibrated instrument at high and low end or operating range 2) Error in the master part measurements 3) Worn instrument 4) Design of the measurement instrument
4 Causes of Reluctant participating team member
Causes of Reluctant participating team member 1) No stake in team outcome 2) Intimidated by other team members 3) Transitioning out of current job function or organization 4) Fear of job loss or voicing opinions
Causes of 'Rush to accomplishment"
Causes of Rush to accomplishment 1) Unrealistic deadline 2) Untrained team members 3) Looking for short-term gains
Central Limit Theorem
Central Limit Theorem 1) Assumption : The sum of the "n" INDEPENDENTLY distributed random variables is approximately normal regardless of the distribution of the individual cariables. 2) The approximation improves as n increaes
Central location, width, spread, and shape can visualized on which tool? a. p-chart b. affinity diagram c. pareto diagram d. histogram
Central location, width, spread, and shape can visualized on which tool? a. p-chart b. affinity diagram c. pareto diagram d. histogram D= histogram
Challenges associated with process interactions
Challenges associated with process interactions: 1) Process Ownership = two./ more areas may think they own the process and have final decision authority 2) Sharing information = hiding poor performance or proprietary issues 3) Commonality of measures= finance measures in dollars, production measures in defects or productivity, and engineers measure by design completion 4) Process knowledge/ expertise (eg. manufacturing many not understand supply chain) ***Challenges should be included as potential risks in project plan during risk analysis.
Challenges in GR&R studies
Challenges in GR&R studies 1) One-sided specification 2) Skewed distribution 3) Fully automated equipment with little/no appraiser interaction 4) Destructive testing 5) New product introduction where only a few units are available 6) Multiple station comparison 7) Equipment the requires resetting or calibration after every measurement 8) Incomplete GR&R data
Charter Negotiation and 7 examples
Charter Negotiation Upon presenting the charter to upper management, team may propose a different approach than what was envisioned by management. ---Examples 1) Objectives --eg. final customer may want a huge redesign that was not anticipated. 2) Scope-->Project boundaries may have to be expanded or broken up into small sections or require additional project teams 3) Resources---Management may be called to decide on how to prioritize resources outside of the team's control 4) Project Transition---Additional time or supervision may be needed to transition the project to routine staff. 5) Project Closure---> May have re-consider project closure date due to shifts in customer preference or unexpected succuess or diverse events.
Check sheet vs. check list:
Check sheet vs. check list: People sometimes confuse a check sheet with a check list. The list we use for groceries and the report you get from the auto repair shop with things checked off after service (oil, filter, tire pressure, tread, etc.) are examples of a check list. The following table highlights some key differences between a check list and a check sheet. 1) Check Sheet a) A tally sheet to collect data on frequency of occurrence b) Custom designed by user c) One of seven quality tools d) E.g.: Check sheet to document reasons for interruptions in OR .
Chi- Square Test
Chi- Square Test Applied in two Ways: 1) Comparing variances when the population variance is known 2) Comparing observed and expected frequencies of test outcomes when there is no defined population variance (attribute data) 3) Unlike Z and t distribution, the tails of the chi-square distribution are non-symetricals
Significance test using nominal data
Chi-Square test Significance test using nominal data
Which Inference Test? Test a sample variance against a known variance
Chi-square Test a sample variance against a known variance
Chi-square Distribution
Chi-square Distribution 1) Summing the squares of standard normal random variables 2) Distribution with regenerative property 3) Gamma distribution with failure rate of 2, and the [Degrees of freedom =2/no. of DF]
Company struggling with low performance in terms of quality, profitability, and productivity is considering a six sigma initiative. Decision to proceed would be considered: A. Smart, lot of low-lying fruit B. Unwise, probably can't afford the effort C. Unwise, they need to attend to basic activities first D. Smart, they have obviously need the six sigma structure
Company struggling with low performance in terms of quality, profitability, and productivity is considering a six sigma initiative. Decision to proceed would be considered: A. Smart, lot of low-lying fruit B. Unwise, probably can't afford the effort C. Unwise, they need to attend to basic activities first D. Smart, they have obviously need the six sigma structure C- Correct
Components of project documentation
Components of project documentation: 1) Goals/ objectives 2) Project sponsored & stakeholders 3) Project milestones 4) Project budget 5) Project boundaries 6) Roles and responsibilities of project team members 7) List of deliverables 8) Metrics to be used to assess the project's performance
Confidence Interval for Mean
Confidence Interval for Mean ***Confidence intervals for the mean are symmetrical about the average. 1) Continuous Data/ Large Samples----> use Normal Distribution 2) Continuous Data/ Small Samples ( less than 30) -------> use t- test
Confidence Interval for Proportion
Confidence Interval for Proportion For large sample sizes, with n(p) and n(1-p) greater than or equal to 4 or 5, the normal distribution can be used to claculate a confience intercal for proportion.
Confidence Interval for Variation
Confidence Interval for Variation 1) Based on Chi-square Distribution-----> distribution of a sum of the squares of k independent standard normal random variables. 2) The mean of a Chi Square distribution is its degrees of freedom. Chi Square distributions are positively skewed, with the degree of skew decreasing with increasing degrees of freedom. As the degrees of freedom increases, the Chi Square distribution approaches a normal distribution.
Confidence Interval for the Mean: Z-distribution & t-distribution?
Confidence Interval for the Mean The CI for the mean represents the sample mean +/- confidence factor * a measure of variability. If the population standard deviation IS known, reference the Z-distribution table. If the population standard deviation IS NOT known, reference the t-distribution table. As the t-distribution sample size increases it behaves like z-distribution and t-value approaches 0. For a given level of confidence, the t-distribution becomes a flatter "bell" curve with the t-statistic increasing as the sample size decreases.
Confidence Interval on Proportion
Confidence Interval on Proportion 1) Percentage of samples in the confidence interval will include the true error rate 2) Example---> 90% error rate means that 9 out 10 will have included the true error rate. 3) CI of the mean decreases as the sample increases--->As more samples are obtained, fewer values are required to create confidence interval. 4) If standard deviation Known, use z-table---> If unknown, then use T-tables 5) Process stability cannot be determined by the fact that a particular sample falls within the confidence interval. ----> Must confirm process stability with statistical control chart.
Confidence Interval on the Mean of a Normal Distribution, Variance Known
Confidence Interval on the Mean of a Normal Distribution, Variance Known • In the previous chapter we illustrated how a parameter can be estimated from sample data. However, it is important to understand how good is the estimate obtained. • Bounds that represent an interval of plausible values for a parameter are an example of an interval estimate. • Interpreting a Confidence Interval • The confidence interval is a random interval • The appropriate interpretation of a confidence interval (for example on μ) is: The observed interval [l, u] brackets the true value of μ, with confidence 100(1-α). • Confidence Level and Precision of Error The length of a confidence interval is a measure of the precision of estimation. 8-2
Confidence Interval
Confidence Interval: 1) Assumes normal distribution and a stable, unchanging population 2) Measure stage---> used to estimate process average when a process control cannot be set because of lack of data. ---> Process average used for baseline estimates 3) Analyze Stage---> Used to examine similarities or differences between samples means taken during various process conditions
Confidence Intervals for Coefficient of Variation
Confidence Intervals for Coefficient of Variation An interval estimate for population parameters where the mean is NOT symmetrical about the average and exhibits chi-square distribution. Coefficient of variation describes the variation in evaluating results from various populations.
Confidence Intervals for the Mean
Confidence Intervals for the Mean: An interval estimate for population parameters where the mean is symmetrical about the average. If the distribution is normal or the population standard deviation is known for a large sample size, one can use the normal distribution to calculate the confidence interval for the mean. A confidence interval for a mean is a range of values within which the mean (unknown population parameter) may lie. Examples of Confidence Interval for a Mean* A Web master who wishes to estimate her mean daily hits on a certain webpage. * An environmental health and safety officer who wants to estimate the mean monthly spills.
Confidence intervals on the Mean with Variance unknown
Confidence intervals on the Mean with Variance unknown 1) Interval between 2 statistics that includes the true value of the probability---> gives information on frequency. 2) If the population variance σ2 is unknown, we can no longer use the normal distribution and instead have to use the t-distribution to calculate confidence intervals Its exact shape is determined by one parameter called the "degrees of freedom". Table 1.1 gives critical values of Student'st-distribution with various degrees of freedom. These numbers depend on two quantities: ν, the degrees of freedom, and p,a probability.
What to consider when using Confidence interval?
Confidence intervals only assess sampling error in relation to the parameter of interest. (Sampling error is simply the error inherent when trying to estimate the characteristic of an entire population from a sample.) Consequently, you should be aware of these important considerations: As you increase the sample size, the sampling error decreases and the intervals become narrower. If you could increase the sample size to equal the population, there would be no sampling error. In this case, the confidence interval would have a width of zero and be equal to the true population parameter. Confidence intervals only tell you about the parameter of interest and nothing about the distribution of individual values.
Considering only total Productive Maintenance methodology process defect are like to result from? a. poor operator training b. setup and adjustment c. incoming defective material d. malfunctioning equipment
Considering only total Productive Maintenance methodology process defect are like to result from? a. poor operator training b. setup and adjustment c. incoming defective material d. malfunctioning equipment D= correct In the real word, all of these options can create process defects In TPM, the assumption is that operators are well-trained, incoming materials meet specifications, and setup and adjustments are minimized.
Considering that all of the following terms have benefits,which wold affect product quality to the greatest extent? A. Elimination of Muda B. Work cell skills matrices C. Lean manufacturing D. Widespead use of load leveling
Considering that all of the following terms have benefits,which wold affect product quality to the greatest extent? A. Elimination of Muda B. Work cell skills matrices C. Lean manufacturing D. Widespead use of load leveling A- correct-- (C) would help quality but have greater effect on items like delivery
Statistical Term: Distributions containing infinite (variable) data points that may be displayed on a continuous measurement scale.
Continuous Distributions: Distributions containing infinite (variable) data points that may be displayed on a continuous measurement scale.
Define Control Chart
Control Chart 1) Test of the hypothesis that the process is in a state of statistical control 2) Point plotting within the control limits is equivalent to failing to reject the hypothesis of statistical control. *Detects only Assignable Variation
Control Chart Methods
Control Chart Methods 1) Mathematical Model for variability study using average and range and requires 2-3 replications by 2-3 appraisers on 1- parts.
Conversion of Attribute Data to Variable Data
Conversion of Attribute Data to Variable Data 1) When collecting data, there are opportunities for some types of data to be either variable or discrete. 2) Consider costs when deciding to collect which type of data. ---> Measuring instruments are most costly for variable data 3) Variable data requires storing of individual value and computations of the mean, st. deviation, and other population estimates 4) Attribute data requires minimal counts of each categoty so little data storage space needed. 5) Manual Collection ---> Variable Data requires more skill than attribute data.
Conversion of Attribute Data to Variable Measures
Conversion of Attribute Data to Variable Measures 1) Variable data more expensive (instrument & data storage costs) 2) Variable data requires storage of individual data and computation of mean, std. deviation, and population estimates 3) Variable require more skilled personnel
Converting from Cpk to a Z-score
Converting from Cpk to a Z-score With a normally distributed set of data an approximation of Z from Cpk and vice versa can be made in substituting and solving within these two formulas. What is the Cpk approximated from a 6 sigma performance? Substituting the Z formula in Cpk (USL) and plugging in 6 for Z from the given data gives: Relating Cpk to sigma (Z) Cpk of 2 corresponds to approximately 6 sigma (short term) performance or 4.5 sigma (long term). The Z in the above formula refers to a short term sigma, short term Z.
Correlation coifficents are generated from which type of graph?
Correlation coifficents are generated from which type of graph? Scatter diagram
Correlation verses Causation
Correlation verses Causation: 1) Two variables may be causally associated or correlated but that doesn't mean cause-and-effect relationship exists between the variables 20 Must have several different observational studies to show that correlation crosses into cause-and-effect relationship.
Relationship between two or more sets of data; Measures the strength and direction of relationship between variables
Correlation: Relationship between two or more sets of data; Measures the strength and direction of relationship between variables
Define cost performance index
Cost Performance Index 1) measures the project performance in dollar terms (ratio of value earned [budgeted cost of work performed] verses the actual cost of work performed). 2) Ratio of 1 or higher is the desirable condition.
Cost of Poor Quality
Cost of Poor Quality: 1) Costs associated with providing poor quality products/services 2) 4 categories of Cost: a) Failure Costs ----> 2 types : I) Internal Failure Costs = costs associated with defects found BEFORE customer gets the product II) External Failure Costs = costs associated with defect found after customer receives the product/service b) Appraisal Costs = Cost incurred to determine the degree of conformance to quality requirements c) Prevention Costs = Cost incurred to keep failure and appraisial costs to a minimum
Percent of work accomplished on Budget
Cost performance index = Percent of work accomplished on Budget
Countermeasure for Dominant team member
Countermeasure for Dominant team member 1) Effective moderation 2) Team leader initiates round-robin for equal opportunity
Countermeasure for Floundering team member
Countermeasure for Floundering team member Definition: Team in progressing in unsteady, faltering manner 1) Team leaders should be visibly present at meetings and decisions 2) Leaders should focus the team on not getting distracted by organizational events 3) Leaders should address concerns to be heard 4) Reinforce management support and commitment when team starts to challenge the purpose of the team.
3 Countermeasures for Group think
Countermeasure for Group think 1) Bring independent members from outside to participate 2) Rotate roles & responsibilities of members at milestones 3) Management by fact
Countermeasure for Overbearing team member
Countermeasure for Overbearing team member 1) Use support of influential team member 2) Round-robin voicing of options 3) Nominal group technique 4) Informal meeting setting 5) Keeps experts and influential teams member as an extension of team
2 Countermeasures for Reluctant participating team member
Countermeasure for Reluctant participating team member 1) Greater support from leaders 2) Protect team members voicing opinions
Countermeasures for 'Rush to accomplishment"
Countermeasures for 'Rush to accomplishment" 1) Team leadership asks for data collection, analysis, and statistical significance. 2) Ask for alternative solutions 3) Revise the deadline to ore realistic one based on resources.
Countermeasures for Attribution in Team Dynamics
Countermeasures for Attribution in Team Dynamics: 1) Team leaders challenge assumptions made by team members 2) Use devil's advocate approach 3) Ask for analysis behind the conclusions drawn.
2 Countermeasures for unquestioned acceptance of facts?
Countermeasures for unquestioned acceptance of facts? 1) Team Leader requests supporting data, analysis and conclusions that are statistically valid 2) Question the assumption behind the analysis
Define Cpk
Cpk Calculation The Cp is the best a process can perform if that process is centered on the midpoint and the Cp = Cpk. The addition of "k" quantifies the amount of which a distribution is centered. A perfectly centered process where the mean is the same as the midpoint will have a "k" value of 0. The minimum value of "k" is 0 and the maximum is 1.0.
Difference between Cp and Cpk?
Cpk also requires input from the customer for the lower specification limit (LSL) and upper specification limit (USL). There are two calculations from the formula providing two values for Cpk. Select the MINIMUM value as the Cpk and to serve as the baseline value. This minimum value must be equal to or greater than the minimum acceptability level. Unlike Cp (and Pp), the Cpk (and Ppk) index can be calculated using unilateral or bilateral tolerances. If only one specification is provided (unilateral) the use the value that involves that specification limit. There will not be a minimum (or maximum), just calculate using the formula that has a specification and use it for the Cpk value. The standard Cpk level is 2.0 for a process in six sigma quality control . The acceptability levels for Cpk depends on your customer.
Critical Path Method & Crashing an Activity
Critical Path Method & Crashing an Activity: 1) Each activity has a normal cost and time for completion. 2) When an activity is "crashed", the time is reduced and costs increased. **** Crash = to apply more resources to complete an activity in shorter time. 3) Incremental Cost-----> (Incremental Cost) / (Time saved to crash each activity on the critical path) The activity with lowest Incremental cost per time---> Must be crashed first to complete project in shorter period
Critical Path Method--5 Unique Features
Critical Path Method--5 Unique Features 1) Emphasis is on activities 2) Time & Cost factors for each activity are considered. 3) Only activities on the critical path are contemplated. 4) Activities with the lowest crash cost (per incremental time salving) are selected first. 5) As an activity is crashed, it is possible for new critical path to develop
Cumulative Distribution Function
Cumulative Distribution Function 1) a function whose value is the probability that a corresponding continuous random variable has a value less than or equal to the argument of the function. 2) In the case of a continuous distribution, it gives the area under the probability density function from minus infinity to x. Cumulative distribution functions are also used to specify the distribution of multivariate random variables.
How are customers segmented?
Customers can be grouped into segments, with this segmentation driven by customers requirements and includes the following categories: 1) Internal and external customers 2) Age groups especially for consumer products 3) Geographical location, including climate, language, ethnicity, and ect. 4) Industry type
DOE & Process Capabilities
DOE & Process Capabilities DOE can be used to find process capabilities ---> objective is optimum values of process variables which yield the lowest process variation.
Data Coding
Data Coding Efficiency of data entry and analysis is frequently improved by data coding---Sometimes it is more efficient to code data by adding, subtracting, multiplying or dividing by a factor. 1) Types of Data Coding a) Substitution - ex. Replace 1/8ths of an inch with + / 1 deviations from center in integers. b) Truncation- Ex. data set of 0.5541, 0.5542, 0.5547 - you might just remove the 0.554 portions. 2) Effects of Coding Data a) Will affect the mean to the extent that the mean must be uncoded for reporting purposes. b) Coding and uncoding of the mean will be exactly opposite. (Ex. Add X, subtract X or multiply by X, divide by X.) c) The effect the coding has on standard deviation depends on how the data is coded.
Data Coding by Substitution
Data Coding by Substitution 1) Consider a dimensional inspection procedure in which the specification is : [(nominal) +/- (deviation from nominal)] 2) Measurement Resolution = 1.8 inch 3) Inspectors record the Standard Deviations 4) Data can be coded as integers expressing the number of 1/8 increments deviating form nominal. 5) Example of data entry (32 - 3/8 inches) crammed onto check sheet----> Recommended Solution-= Either make the check sheet blocks bigger at the risk of having fewer samples and plot points per page
Data Coding by Truncation of Repetitive Place Values
Data Coding by Truncation of Repetitive Place Values Measurements such as 0.55303, 0.55308, 0.55310----> The digits 0.553 is repeating in all the observations can be recordeds as the last digits expressed as integers
Data points: 64.7, 37.5 28.9, 55.6, 42.5, Calculate coifficient of variation
Data points: 64.7, 37.5 28.9, 55.6, 42.5, Calculate coifficient of variation Mean is 45.84. St. deviation = 12.976 COV= mean/ St. dev= 27.9% Note that using a standard deviation of 14.306 will give COV-31.2% the wrong answer
Dealing with Process out-of- control in process capability study
Dealing with Process out-of- control in process capability study 1) Center the process and determine % of noncoformace outside specification limits 2) Process variation is less than No. of nonconformance ---> Reduce the # of nonconformance. 3) Reduce variations or revise specification limits.
Statistical Term: Distributions used to make decision and construct confidence intervals
Decision Distribution: Distributions used to make decision and construct confidence intervals
Defect levels , as reported by Motorola, are higher than one might expect from use of a standard normal table or traditional capability calculations. Why is this true? A.Motorola found their processes followed the exponential distribution B. Motorola allowed fro failure on one-tail only c. Motorola allowed for a 1.5 sigma shift in the mean d. Motorola found that six sigma efforts increased process variation.
Defect levels , as reported by Motorola, are higher than one might expect from use of a standard normal table or traditional capability calculations. Why is this true? A.Motorola found their processes followed the exponential distribution B. Motorola allowed fro failure on one-tail only c. Motorola allowed for a 1.5 sigma shift in the mean d. Motorola found that six sigma efforts increased process variation. C-correct---used 1.5 standard devations to "safely"reort defect levels and process improvements
Defects per million opportunities (DPMO)
Defects per million opportunities (DPMO) DPO= (DPU) / ((Total number of opportunities)
Defects per unit (DPU)
Defects per unit (DPU) = (Total number of defects) / (Total number of products produced in a time period)
Define Gantt Chart
Define Gantt Chart 1) Bar chart that only indicates an ambiguous description of how the project, as a system, reacts to changes
Define process performance measures
Define Process performance measures: Measure of how the process is executing against some established goals or statistical measure.
Define the sample space S (rock, book, cigar, guitar, dog), What is the compliment of (Cigar, dog) ? a. rock, book, cigar, guitar, dog b. cigar, guitar, dog c. dog d. rock, book, guitar
Define the sample space S (rock, book, cigar, guitar, dog), What is the compliment of (Cigar, dog) ? a. rock, book, cigar, guitar, dog b. cigar, guitar, dog c. dog d. rock, book, guitar D= answer Compliment of an envet is a set of all the elements not in the event. The sample space S has 5 elements: (rock, book, cigar, guitar, dog. Elements rock, book, guitar are not in the event (cigar , dog)
Definition of Process Analysis and Documentation
Definition of Process Analysis and Documentation 1) Process= set of interrelated resources and activities that transform input into outputs with the objective of adding value. 2) Activities within any process should be documented and controlled
Deming & Business Process Management
Deming & Business Process Management Deming defines the supplier-process-customer Model: 1)Process outputs, controls, & outputs are inter-dependent 2) Statistical methods can improve process control and guide improvements 3) Process feedback can be used to re-design products and processes and improve overall business results ***BPM represents a major advance in the quality improvement thinking by managing the entire process---as opposed to traditional management process that operate as silos.
Describe Critical-to-Cost metrics
Describe Critical-to-Cost metrics 1) identifies areas of the process that raise the expense 2) Should not include only the typical cost of task, but also the increased cost of errors in the performance of this task. 3) Should include the probability of the error. 4) If lag time is present---> Include the cost of keeping product on hand
Describe Critical-to-Quality Metrics
Describe Critical-to-Quality Metrics Definition= amount of money required to align a product/service with quality baselines 1) Yeild--amount of completed product divided by the amount of product that began the process.---> Does not aid in location of process errors or tell which parts can be salvaged 2) If the yeild= 95%, then scrap rate is 5% 3) Rolled Throughput ---average % of units with no defects---measures the expected quality level after several steps ----better than yeild
Describe Process Definition
Describe Process Definition 1) First step in Measure Stage= Create a comprehensive process level map of processes currently performed.----aka. group describes all the activities that they plan to improve 2) Expert employee participation needed to create detailed process map because employees have a different conception of process sequence than their superiors. 3) Employees, often , would have streamlined and modified process with notification of management---> harmful to criticize or judge the customization made by employees------> best to focus on creating an accurate process map.
Describe the Critical-to-Schedule Metrics
Describe the Critical-to-Schedule Metrics 1) Cycle time= most common metric----aka. delivery time, order processing time, or downtime. 2) Requires distinction between NVA and VA activities to improve Cycle time 3) Cycle time is secondary in importance to cost or quality.
Describe the importance of identifying key decision points during Measure stage
Describe the importance of identifying key decision points during Measure stage 1) After creating a process map, must identify the important decision made during the process. 2) Team members are alert to areas of inefficiency, requiring excess decision-making. 3) Team should try to reduce the number of decision made every time a process is performed. 4) Since process has not been measured, then all measurements must reflect the process as typically performed----> to ensure proper targeting of improvement efforts. 5) Team leaders communicate info to stakeholders.
Describe the process performance indices, including their application to the measure stage of DMAIC
Describe the process perfoRmance indices, including their application to the measure stage of DMAIC 1) Process performanc index---> tells whether a particular batch of material will be satisfactory to customer 2) Key difference between process performance index and process capability---> Pp limited to single batch. 3) Process performance index used to create process baseline estimates for uncontrolled processes------> requires large sample size. 4) Statistical control is preferred over Process performance index but can't be done if process lacks statistical control or insufficent data.
Describe the use of enumerative statistics in process baseline estimation
Describe the use of enumerative statistics in process baseline estimation 1) In estimation of a process baseline, enumerative statistics used to evaluate random samples from populations. 2) Enumerative statistics can determine whether samples represent the population, meaning that they were drawn without bias. 3) Confience level intervals of 95% used. 4) Drawback of Enumerative Statistics----> they are drawn from static, unchanging population.--but Six Sigma needs information from dynamic process and uses analytical statistics.
Descriptive Statistics
Descriptive Statistics Includes: 1) Central Tendency 2) Measures of Dispersion 3) Probability Density function 4) Frequency Distribution 5) Cumulative Distribution
Design of p-charts
Design of p-charts 1) 3 parameters of the p-chart------sample size, sampling frequency and control limits
Determine the coefficient of variation for the last 500 pilot plant test runs of high temperature film having a mean of 900 degrees Kelvin with standard deviation of 54 degrees. a. 6% b. 16.7% c. 0.6% d. 31%
Determine the coefficient of variation for the last 500 pilot plant test runs of high temperature film having a mean of 900 degrees Kelvin with standard deviation of 54 degrees. a. 6% b. 16.7% c. 0.6% d. 31% A= Correct % Coefficient of Variation = S/ (X-bar) * 100 54/ 900 * 100 = 6%
Determining Stability & Normality:
Determining Stability & Normality: 1) Common Cause Variation ---> process output is stable and predictable 2) Special cause variation --> Unpredictable output and out-of-control
How to Determine if process in control?
Determining if process is in control: Use time-series and SPC charts to determine process control. If the process is out of control (i.e. still rising with upward trend), then assessing the current process is not likely to reflect the long term performance.
Determining the impact severity is done using what data?
Determining the impact severity is done using what data? 1) Risk analysis of like data 2) historical data 3) Brain storming
Developing Sampling Plans
Developing Sampling Plans 1) Depends on the purpose and whether there are customer or standards requirements for the study. 2) Process currently running and in control ---> use control chart to calculate process capability indices 3) Process normally distributed and in control ---> standard deviation = R-bar / d(2)
Developing Sampling Plans
Developing Sampling Plans: **Sample plan depends on purpose and customer requirements for the study 1) If the process is currently running and is in control-----> use control chart to calculate the process capability indices. 2) If it is project proposal for a new process---> use a pilot run to estimate process capability ----> Drawback= estimated process variability is less than the process variability of an ongoing process. 3) If trying to improve the process---> use Design of Experiments to get the optimum values of the process variables which yield the lowest process variation
Developing an SIPOC Diagram
Developing an SIPOC Diagram: 1) Team will create process map that will be posted on the meeting room wall 2) 4-5 key steps in a process. 3) Process outputs---product/ service of this process. 4) Customers of the process outputs (end users) 5) Process inputs / Materials 6)Suppliers of the process 7) Identification of preliminary customer requirements 8) Involvement of stakeholders, team leader, and champion for verification.
Diameter of a population of ball bearings is normally distributed with a mean of 75 and sigma of 8. What is the average diameter of 10 randomly selected ball bearings being greater than 77?
Diameter of a population of ball bearings is normally distributed with a mean of 75 and sigma of 8. What is the average diameter of 10 randomly selected ball bearings being greater than 77? N= 10 sigma = 8 mean= Standard deviation of sample of 10 is equal tot he standard deviation of the individuals divided by the square root of the sample size. Standard deviation of the average with a sample of 10 is 2.53. Transform to standard normal using (mean= 0 and standard deviation =1) Z= (X - mean) / sigma Z= (77 - 75) / 2.53 = 0.7906. Area under the standard normal curve to the right of 0.7906 is 0.2146 Answer= 0.2146
Summary of analytical and Enumerative Studies
Difference between Enumerative study & Analytic Study: 1) Analytical studies start with hypothesis statement made about population parameters 2) Sample statistic used to test hypothesis and either reject/accept null. 3)
Difference between Enumerative study & Analytic Study
Difference between Enumerative study & Analytic Study: Enumerative study = study in which action will be taken in the universe Analytic study= study in which action will be taken on a process to improve performance in the future.
Difference between Risk Analysis and Risk Management
Difference between Risk Analysis and Risk Management" Risk Analysis is part of larger methodology called Risk Management. Risk management is more inclusive process of dealing with risk and is divided into 4 phases (risk planing, Risk Assessment, Risk Handling, & Risk Monitoring )
Difference between natural process limits vs. specification limits
Difference between natural process limits vs. specification limits 1) Natural process control limits = process in statistical control and meets specification or is +/- 3sigma 2) Specification limits= expectations of the customer or designer 3) Capable Process= process variation is significantly lower then width of specification limits (upper and lower limits)
Difference between repeatability & reproducibility
Difference between repeatability & reproducibility Precision = describes the variation you see when you measure the same part repeatedly with the same device. It includes the following two types of variation: 1) Repeatability = Equipment measurement variation (same operator) 2) Reproducibility = appraiser measurement variation (different operator, same part) Both are expressed as standard deviation.
Difference between strategic quality goals and strategic business plans is that : A. Strategic quality goals are often a lower tier than the strategic business plan B. They are determined by top management only C. They may offer conflicting priorities d. They are based on priorities by all levels of the company.
Difference between strategic quality goals and strategic business plans is that : A. Strategic quality goals are often a lower tier than the strategic business plan B. They are determined by top management only C. They may offer conflicting priorities d. They are based on priorities by all levels of the company. A- correct---> Band D are common to both strategic quality goals and strategic business plan. C- wrong because strategic business plan forms the higher level with strategic quality goals being part of it.
2 Disadvantage of PERT
Disadvantage of PERT 1) Complexity of PERT increases implementation problems 2) More data is required as network inputs
Statistical Term: Distributions resulting fro countable (attribute) data that has a finite number of possible values
Discrete Distributions: Distributions resulting fro countable (attribute) data that has a finite number of possible values
Discuss the identification of process metrics during the Measure Stage
Discuss the identification of process metrics during the Measure Stage: 1) Factors critical to schedule (CTS) ----> impact project completion date 2) Factors critical to quality (CTQ) ---->Direct effect on the desired characteristics of the product/ service. 3) Factors Critical to Cost (CTC)----> impact materials, labor, delivery, overhead, inventory and/or cost to the consumer of the good or service. 4) Metrics should be customer-focused and transparent; that is they should be objective 5) Metrics need to repeatable and reproducible
Distribution of average approach a normal distribution with sample sizes of 25 are taken. Statement applies to: a. only normal distribution, according to the central limit theorem b. only triangular distribution, according to the central limit theorem c. only uniform distribution, according to the central limit theorem d. All distributions, according to the central limit theorem
Distribution of average approach a normal distribution with sample sizes of 25 are taken. Statement applies to: a. only normal distribution, according to the central limit theorem b. only triangular distribution, according to the central limit theorem c. only uniform distribution, according to the central limit theorem d. All distributions, according to the central limit theorem D= correct. Regardless of shape of the original distribution of the means from the samples (n= 25) will follow normal distribution Section VII --11/12
Document Archieving
Document Archieving 1) Final state of project and includes a) Test data b) Traceabilty of materials c ) Key project variables d) Consideration of duplicate copies at different sites e) Use of medium with a life longer than record retention period
Downward Flow of Communications & typical types of information
Downward Flow of Communications 1) The flow of information from team leaders/ managers to team members/ peers 2) Type of Information : a) Staff and team instruction s b) Rationale for instructions to team members c) Policies and procedure of the company d) Team member performance feedback 3) Key disadvantage= Filtering of information or distortion as it is passed down.
Drawback of Cp and Pp?
Drawback of Cp and Pp? Cp and Pp are measurements that do not account for the mean being centered around the tolerance midpoint. The higher these values means the narrower the spread (more precise) of the process. That spread being centered around the midpoint is part of the Cpk and Ppk calculations. The midpoint = (USL-LSL) / 2 The addition of "k" quantifies the amount of which a distribution is centered. A perfectly centered process where the mean is the same as the midpoint will have a "k" value of 0. The minimum value of "k" is 0 and the maximum is 1.0. An estimate for Cpk = Cp(1-k). and since the maximum value for k is 1.0, then the value for Cpk is always equal to or less than Cp.
Drawbacks of Range Method
Drawbacks of Range Method 1) Does not quantify repeatability & reproducibility separately ---> to do so, use ANOVA or Average and Range method
During variable control charting, a trend of 4 consecutive points is noted on both the average and range charts. the average chart is increasing and the range chart is decreasing. Conclusion??
During variable control charting, a trend of 4 consecutive points is noted on both the average and range charts. the average chart is increasing and the range chart is decreasing. Conclusion?? No conclusion can be made.
Effect of Gauge R& R?
Effect of Gauge R& R? 1) Measurement system play main role in process capability assessment ---> higher the gauge R& R, the higher the error in C(p) assessment
Effective control charts subgrouping includes which of the following actions? a. Group product so that the subgroups are heterogeneous as possible b. Group product produced over a long period of time c. Group product to achieve a minimum opportunity for variation between subgroups d. Group product to be representative of production over short time period
Effective control charts subgrouping includes which of the following actions? a. Group product so that the subgroups are heterogeneous as possible b. Group product produced over a long period of time c. Group product to achieve a minimum opportunity for variation between subgroups d. Group product to be representative of production over short time period D= Correct Product is subgrouped for control charting by means that include: 1) product produced as nearly as possible at one time 2) groups that achieve maximum opportunity for variation from one subgroup to another 3) groups that are represenative of ALL production over a given period of time. 4) Product is grouped to be as homogenous as possible.
Ensuring Data Accuracy & Integrity
Ensuring Data Accuracy & Integrity Data should not be removed from a set without an appropriate statistical test or logic. Generally, data should be recorded in time sequence. Unnecessary rounding should be avoided. If done, should be late in the process. Screen the data to remove entry errors. Avoid emotional bias. Record measurements of items that change over time as quickly as possible after manufacture and again after the stabilization period. Each important classification identification should be recorded alongside the data. (Ex. Time, machine, operator, gage, lab, material, conditions, etc).
Ensuring Data Accuracy and Integrity
Ensuring Data Accuracy and Integrity Bad Data corrupts decision-making process---Preventions methods: 1) Avoid emotional bias relative to targets/ tolerance wh/ counting/ measuring/ recording 2) Time-sequenced data---> Record by order of capture 3) Avoid Rounding (reduces measurement sensitivity) & Calculate average to one more decimal than individual readings 4) Use objective statistical tests to identify outliners 5) Select sampling plan based on analyst's specific needs & experience. 6) Screen & filter data to detect & remove data entry errors 7) To apply statistics assuming normal population, ask if expected dispersion can be represented by 8-10 resolution increments-----> If no, then default statistic may be the count of observations which do or don't meet specification criteria. 8) Make sure that your data has labels
Enumerative (Descriptive) Studies
Enumerative (Descriptive) Studies 1) Classification of people into intervals of income, age, or health (Eg. census study) 2) Graphical tools
Ergonomics reduces injuries and lost production . Which of the following are sound ergonomic principles in the work place? a) long lead times b) changing employees to fit the workplace c) use of forklifts and conveyors d) Job rotations and stress reduction
Ergonomics reduces injuries and lost production . Which of the following are sound ergonomic principles in the work place? a) long lead times b) changing employees to fit the workplace c) use of forklifts and conveyors d) Job rotations and stress reduction D-correct (Section III-- 18/19)
Error variance in an R&R study means?
Error variance in an R&R study means? Measurement error or repeatability
Errors in performing Gauge R& R?
Errors in performing Gauge R& R? 1) In process control situations, not sampling covering the tolerance spread ---> best to pick sample outside of specification limit rather than random samples 2) Knowledge bias in repetitive measurement trials due to failure to randomize samples during measurement 3) Inflated reproducibility errors due to untrained appraiser 4) Absent experimenter during study (remote located experimenter) --> can automate measurement but need to present during the human involvement 5) Publishing results with appraiser names (future uncooperative appraisers) 6)Assuming that GR&R is the same for all equipment or that results are valid forever
Essence of kanban concepts includes what? a. delivery of components and products ahead of need b. minimal storage in production areas c. minimal distress in the production system when a machine failure occurs d. wide applicability to repetitive and non-repetitive production plants
Essence of kanban concepts includes what? a. delivery of components and products ahead of need b. minimal storage in production areas c. minimal distress in the production system when a machine failure occurs d. wide applicability to repetitive and non-repetitive production plants B= correct. Kanban is not applicable to one-of-a -kind
Exponential Distribution
Exponential Distribution 1) Basic assumptions: a) Family of distributions characterized by its m b) Distribution of time between independent events occurring at a constant rate c) Mean is the inverse of the Poisson distribution d) Shape can be used to describe failure rates that are constant as a function of usage
Exponential Distribution
Exponential Distribution 1) Models Reliability or the time to failure of a component or system. 2) λ is the failure rate and 1/ λ is Mean time to failure. 3) λ is the probability that a value of exponential random variable is less than its mean.
Expression below is formula for which distribution? n! ______ (p ^x) (1-p) ^ n-x x! (n-x)!
Expression below is formula for which distribution? n! ______ (p ^x) (1-p) ^ n-x x! (n-x)! Answer= t- distribution Knowing the relationships between reliability distributions and tests, this question implies sampling distribution. that eliminates the normal and exponential continuous modeling distributions. The chi-square test deals with variances, while the t-test is a sample means test VII- 23/23
External Failure Costs
External Failure Costs 1) Penalties 2) Pricing Errors 3) Liability suits 4) Loss of market share 5) Customer complaint visits 6) Recalls 7) Cost of restocking/repair/ rework 8) Premium Freight
F-distribution Application
F-distribution 1) Test for equality of variance from two normal populations (ANOVA) 2) Type of cumulative distribution function
F-test
F-test F test - test of whether two samples are drawn from different populations have the same standard deviation, with specified confidence level. Samples may be of different sizes. The F-Test used in the hypothesis testing of variances as in ANOVA. The F-Test assumes a normally distribution, as well as Bartlett's Test. The samples should exhibit normal conditions within each set of experiments (or trials). The value of F represents the ratio of two variances, and comparing the F-test value to the F-critical value is used to make a decision on the null hypothesis. It is used to compare: 1 Sample Variance to a Target 2 Sample Variances >2 Variances use ANOVA In ANOVA, the value of F is the ratio of treatment variance to the error variance.
Tests if two sample tests are equal
F-test Tests if two sample tests are equal
FMEA authorities suggest that FMEA review should be composed of: A. Design engineer and one independent party B. 5-10 qualified team members C. Designer, producer, user D. 3-6 design engineers
FMEA authorities suggest that FMEA review should be composed of: A. Design engineer and one independent party B. 5-10 qualified team members C. Designer, producer, user D. 3-6 design engineers B- correct; III-36
FMEAS satisfy which of the following basic organizational needs? A. FMEAS are of little value since they are tedious B. Auditors will not hand out a finding if FMEAs are in compliance C. Bottom line is automatically improved D. Risk of quality defects is greatly reduced
FMEAS satisfy which of the following basic organizational needs? A. FMEAS are of little value since they are tedious B. Auditors will not hand out a finding if FMEAs are in compliance C. Bottom line is automatically improved D. Risk of quality defects is greatly reduced D- correct
FMEAS satisfy which of the follwoing basic organizational needs A. FMEAS are the marginal value since they are very tedious B. Auditors will not hand out a finding if FMEAs are in compliance C. Bottom line is automatically improved D. The risk of defects can be greatly reduced by corrective action
FMEAS satisfy which of the follwoing basic organizational needs A. FMEAS are the marginal value since they are very tedious B. Auditors will not hand out a finding if FMEAs are in compliance C. Bottom line is automatically improved D. The risk of defects can be greatly reduced by corrective action D- correct; Auditors must verify that FMEAS are completed and are in compliance.
Factors that impact quality of conformance
Factors that impact quality of conformance 1) type of manufacturing process 2) work force training 3) quality assurance --processing controls, tests, inspection, actiities
Factors that influence equipment measurement variation (repeatability)
Factors that influence equipment measurement variation (repeatability) 1) Design of measurement system
Factors that influence appraiser measurement variation (reproducibility)
Factors that influence equipment measurement variation (reproducibility) 1) Setting of the work piece (special loading/unloading) 2) Operator training, skill, and knowledge 3) Consistency in measurement
Factors to be considered for initial project selection
Factors to be considered for initial project selection: 1) Broad appeal to team members and management 2) Fairly simple, but no trivial 3) Opportunity for quick benefits 4) Project scope under group's control 5) Selected using time and resource constraints 6) Major benefits are project resolution and learning teamwork
Factors to consider when creating work instructions
Factors to consider when creating work instructions 1) Keep Controlled copies of work instructions where activities performed 2) Can use flow charts with work instructions to show relationship of process steps 3) Consider the level of detail and its appropriateness of the background, experience, and skills of personnel. 4) Involve the people that perform activities when creating work instructions
Cost resulting from products/services not conforming to requirements or customer/user needs that is, the cost from poor quality.
Failure Costs Cost resulting from products/services not conforming to requirements or customer/user needs that is, the cost from poor quality.
Failure modes and effect analysis involves which activity? a. Determination of probability in a specified time period b. Expected number of failures in a given time interval c. study of exactly how a product fails and what causes the failure d. study of probability of success in a given time period
Failure modes and effect analysis involves which activity? a. Determination of probability in a specified time period b. Expected number of failures in a given time interval c. study of exactly how a product fails and what causes the failure d. study of probability of success in a given time period C- correct; FMEAs analyze each failure mode to determine the results of these failures. and do determine how a product will fail and what causes the failure. They don't determine the chance of success or failure
Failure probability level that is highly unlikely would have failure probabilty of 1 in: A. 1,000 B. 10,000 C. 100,000 D. 1,000,000
Failure probability level that is highly unlikely would have failure probabilty of 1 in: A. 1,000 B. 10,000 C. 100,000 D. 1,000,000 D- correct
Feedback Loop
Feedback Loop: 1) Defines the methods for monitoring and adjusting the process if the results are different from expectioatns
Define Final Report
Final Report Definition----->Report Card on performance for completion of objectives, comparison of actual benefts and cost with budgets, and measure of major activity completion data verses milestones
Find the control limt for S-chart, when N= 10, Mean = 40, Sigma = 7, and process is in control.
Find the control limit for S-chart, when N= 10, Mean = 40, Sigma = 7, and process is in control. Answer= 12.0 When N= 10, B4= 1.72 UCL - (B4) (S-bar) = 1.72 * 7 = 12.04
Flow Charts
Flow Charts 1) Process map used to depict the procedures. 2) Often is the starting point for process improvement fo six sigma teams.
For a process with normal distribution, that is centered on the specification limits, assuming no process shift, what is the process capability index, if the non-conformance level is 6.8 ppm a. Cp=1 b. Cp= 1.33 c. Cp= 1.5 d. Cp= 2
For a process with normal distribution, that is centered on the specification limits, assuming no process shift, what is the process capability index, if the non-conformance level is 6.8 ppm a. Cp=1 b. Cp= 1.33 c. Cp= 1.5 d. Cp= 2 C= Correct With no process shift, a ppm= 6.8 has a Cp= 1.5 for a nomral distribution. This can be cound from the table where ppm= 6.8 and z= 4.5 Cp = USL - LSL / 6 SIMGS = 4.5 - (-4.5) / 6 = 1.5
For process with normal distribution, that is centered on specification limits, assuming no process shift, what is the process capability index, if the non-comformance level is 6.8 ppm?
For process with normal distribution, that is centered on specification limits, assuming no process shift, what is the process capability index, if the non-comformance level is 6.8 ppm? Cp = 1.5 is the correct answer The capability index failure rate is shown in the talbe. With no process shift, a ppm = 6.8 has Cp= 1.5 for a normal distribution A ppm= 6.8 is a z-value of 4.5. Cp= (USL - LSL) / 6 SGMA = (4.5 - (-4.5) / 6 = 1.5
For two events, which of the following is a true probability statement? a. P (A or B) = P (A) + P (B) if A and B are independent b. P (A or B) = P (A) + P (B) if A and B are mutually exclusive c. P (A or B) = P (A) * P (B) if A and B are mutually exclusive d. P (A or B) = P (A) * P (B) if A and B are independent
For two events, which of the following is a true probability statement? a. P (A or B) = P (A) + P (B) if A and B are independent b. P (A or B) = P (A) + P (B) if A and B are mutually exclusive c. P (A and B) = P (A) * P (B) if A and B are mutually exclusive d. P (A or B) = P (A) * P (B) if A and B are independent B= correct The question requires a comparison of the answers with the additive and multiplicative laws of probabiliy. (C and D) would be correct if it stated: P (A AND B) = P (A) * P (B) if A and B are independent
Formal and Informal Communications
Formal and Informal Communications 1) Formal communication= official company sanctioned methods of communicating to employees. 2) Informal communications----Links the company to grapevine, rumor mill, ect.---> clarification about the latest policy can be made (tranfer or retirment)
From an upper management perspective, what has been the principal motivating factor in embracing six sigma? A. Bottom line results B. Market share growth C. Defect Reductions D. Customer Focus
From an upper management perspective, what has been the principal motivating factor in embracing six sigma? A. Bottom line results B. Market share growth C. Defect Reductions D. Customer Focus A= correct ---> Crosby one stated that upper management is interested in money.
Function of Machine Capability Study
Function of Machine Capability Study 1) Determine the inherent process (machine) variation by excluding elements like batch-to-batch, stream-to-stream, and time-to-time variation 2) Minimize measurement variability (operator and equipment)
Function of Process Capability Study
Function of Process Capability Study 1) Demonstrates that process is centered within the specification limits 2) Process variation predicts the process is capable of producing parts within tolerance limits
Function of Quality Cost Reports
Function of Quality Cost Reports: 1) Determine the status of cost control efforts 2) Identify opportunities for reducing costs by systematic improvements
Function of SIPOC
Function of SIPOC 1) Identifies essential work flows and sources of variation in work over time 2) Captures key components of success from suppliers through internal processes and on to key customers 3) Other tools (affinity diagrams, process mapping, flow charting) can be used to identify major blocs or steps in the process/ system
Function of Written Procedures
Function of Written Procedures Describes: 1) What is done during the process? 2) Why it is done (Business reason) 3) Where it is done ( Location/ process step) 4) When it is done (trigger)
Gant Charts (Bar Charts) --4 Advantages
Gant Charts (Bar Charts) ---4 Advantages: 1) Charts are easy to understand and change 2) Each bar represents a single activity ( each activity shown as a horizontal bar with ends positioned at the start and end dates for that activity) 3) Only minimal data needed to construct 4) Program task progress verses date is shown
Gant Charts (Bar Charts) --4 DisAdvantages
Gant Charts (Bar Charts) --4 DisAdvantages 1) Inter-dependencies of activities (shown in PERT & CPM) not shown in Gantt 2) No way to indicate variation in the expected activity times 3) Activity details not indicated 4) Little predictive value to this presentation of data
Geometric Distribution
Geometric Distribution Basic assumptions: Discrete distribution Just two outcomes for each trial Trials are independent All trials have the same probability of occurrence Waiting time until the first occurrence
Geometric Distribution Application
Geometric Distribution Application: Number of failures before the first success in a sequence of trials with probability of success p for each trial Number of items inspected before finding the first defective item - for example, the number of interviews performed before finding the first acceptable candidate
Geometric Mean
Geometric Mean is a special type of average where we multiply the numbers together and then take a square root (for two numbers), cube root (for three numbers) etc. The geometric mean is NOT the arithmetic mean and it is NOT a simple average. It is the nth root of the product of n numbers. That means you multiply a bunch of numbers together, and then take the nth root, where n is the number of values you just multiplied. Did that make sense? Here's a quick example: What is the geometric mean of 2, 8 and 4? Solution: Multiply those numbers together. Then take the third root (cube root) because there are 3 numbers. cube Root ( 2 *8* 4) = cube root (64) = 4 Geometric Mean
Given a Cp of 1.7 for a process and the same standard deviation and specification limits for the calculation of Cp indices one would not be surprised to fine what?
Given a Cp of 1.7 for a process and the same standard deviation and specification limits for the calculation of Cp indices one would not be surprised to fine what? Standard deviation is fairly low compared to specification limits
Given an average of 1.93 non-conformities per 5 units, what is the upper limit of the control chart used in the situation?
Given an average of 1.93 non-conformities per 5 units, what is the upper limit of the control chart used in the situation? Number of nonconformities per unit is monitored with a U-chart. Theh upper and lower control limits are symmetrical and the upper control limit is calculated using the expression USL = mean + S ( Square root of u / square root of N) USL = 1.93 + 3 [ the square root 91.93/ 5)] = 3.79
Given the following information : Probability of 1 or more defects = 0.69 Probability of 1 or more defects = 0.34 Probability of 1 or more defects = 0.12 Probability of 1 or more defects = 0.03 What is the probability of 2 or fewer defects?
Given the following information : Probability of 1 or more defects = 0.69 Probability of 1 or more defects = 0.34 Probability of 1 or more defects = 0.12 Probability of 1 or more defects = 0.03 What is the probability of 2 or fewer defects? Answer= 0.88 The question presents typical Poisson data in a slightly different light. However, it boils down to a basic probability question. Probability of 3 or more defects is 0.12, the probability of 2 or fewer defects: 1- 0.12 = 0.88
Goldratt's theory of constraints deals with money in relationship to 3 fundamental measurements for evaluating system. Align the following measures with their monetary equivalents A. Throughput equals money going out B. Inventory equals money stuck inside C. Operational expenses equals money coming in D. Throughput equal money stuck inside
Goldratt's theory of constraints deals with money in relationship to 3 fundamental measurements for evaluating system. Align the following measures with their monetary equivalents A. Throughput equals money going out B. Inventory equals money stuck inside C. Operational expenses equals money coming in D. Throughput equal money stuck inside B- correct (Section II/ 15-16_
Graphical display of total percentage of results below a certain measurement value if called: a. histogram b. probability density function c. cumulative density function d. Expected Value
Graphical display of total percentage of results below a certain measurement value if called: a. histogram b. probability density function c. cumulative density function d. Expected Value C= Correct; (A) and (B) display probabilities over a range of values. Expected value means the average outcome.
Guidance in Project selection & Implementation
Guidance in Project selection & Implementation for the team can come from------> Team leader, green belt, black belt, or facilitator
Guideline for Collecting Data
Guidelines---Methods of Collecting Data 1) Formulate a clear problem statement 2) Define what is measured 3) List all the important measurements to be measured. 4) Select the right measurement technique 5) Construct an uncomplicated data form 6) Decide who will collect the data 7) Arrange for appropriate sampling method 8( Decise who will analyze and report the results *** Data needs an operational definition to have meaning and the ability to control quality ** Manual Data Collection is laborious and prone to error so inferior to automatic data collection. *****Large amounts of data are difficult to analyze unless organized is digestable format---graphs, charts, histograms, and Pareto Diagrams
Harmonic Mean
Harmonic Mean A kind of average. To find the harmonic mean of a set of n numbers, add the reciprocals of the numbers in the set, divide the sum by n, then take the reciprocal of the result. The harmonic mean of {a1, a2, a3, a4, . . ., an} is given below. Harmonic Mean = N/(1/a1+1/a2+1/a3+1/a4+.......+1/aN) Step 1: Find the Harmonic Mean of 1 and 100 H= 2 _____________ = 2 / [101/ 100] = 2/ [1.01] [ 1/1] + [1/ 100] H ≈ 1.98019802
Harry introduced 4 new group of metrics:
Harry introduced new group of metrics: a) Measure customer opionons b) Determine Customer CTQ factors c) Measure product outcomes (throughput yield, rolled throughput yield, normalized yield) d) Correlate process outcomes to CTQ (measure processes with metrics that correlate to the company's fundamental outcomes)
Hearing aids and eye glasses are example of: a. Value stream mapping b. Kanban c. Poka-yoke d. Kaizen
Hearing aids and eye glasses are example of: a. Value stream mapping b. Kanban c. Poka-yoke d. Kaizen C=correct
Histogram
Histogram 1) Approximation of the distribution's shape 2) Normal distribution if symmetrical curve= stable, predictable process 3) Frequency= No. of data points that fall within a given bar 4) Sampling error or lack of randomness if differences between sample data in histogram and the population data curb (Fig. 6.15 pg.VI- 25 of Indiana counsel notes) 4) Natural variation = bell shaped curve is approximate of the distribution shape or variation that close to the bell curve (Se VI-36 Indiana Council notes)
Histogram is also called?
Histogram is also called?---Relative Frequency graph Cumulative frequency graph is called an ogive---this differs from ordinary frequency polygon or histogram in that the frequencies are cumulative. That is, each class frequency is added to the total of all previous class frequency is added to total of all previous class frequenices. Histogram displays distribution of sample, not a population function and is part of relative frequency graph
Histogram used to plot the number of voids found verses the weight of the plastic injection molded part. One would expect the shape of distribution to be: a. normally distributed b. binomial distributed c. decreasing slope d. bimodal
Histogram used to plot the number of voids found verse the weight of the plastic injection molded part. One would expect the shape of distribution to be: a. normally distributed b. binomial distributed c. decreasing slope d. bimodal C- Correct. Not all histograms have normal distribution. In this case, the as the weight of the part increases, there would be fewer voids, or a decreasing slope. The number of voids is the X-axis and the part weight on the Y-asiz. Section VI-31 and logic
Histograms
Histograms 1) Frequency column graphs that display a static picture of process behaviours with a minimum of 50-100 data points 2) "Frequency" =Data points fall withing a given bar or interval 3) Stable Process---> Predictable process; Uni-modal or Bell-shaped curve. 4) Unstable Process---> Exotic shape---> Exponential, Lognormal, Gamma, Beta, Weibull, Poisson, Binomial, hypergeometric, Geometric
Histograms Shapes----Double-peaked or bimodal.
Histograms Shapes---Double-peaked or bimodal. The bimodal distribution looks like the back of a two-humped camel. The outcomes of two processes with different distributions are combined in one set of data. For example, a distribution of production data from a two-shift operation might be bimodal, if each shift produces a different distribution of results. Stratification often reveals this problem.
Histograms Shapes---Skewed distribution
Histograms Shapes---Skewed distribution 1) The skewed distribution is asymmetrical because a natural limit prevents outcomes on one side. 2) The distribution's peak is off center toward the limit and a tail stretches away from it. ****For example, a distribution of analyses of a very pure product would be skewed, because the product cannot be more than 100 percent pure. Other examples of natural limits are holes that cannot be smaller than the diameter of the drill bit or call-handling times that cannot be less than zero. These distributions are called right - or left-skewed according to the direction of the tail.
Histograms Shapes------Truncated or heart-cut.
Histograms Shapes---Truncated or heart-cut. 1) The truncated distribution looks like a normal distribution with the tails cut off. 2) The supplier might be producing a normal distribution of material and then relying on inspection to separate what is within specification limits from what is out of spec. The resulting shipments to the customer from inside the specifications are the heart cut.
Histograms Shapes---Normal Distribution
Histograms---Normal Distribution The number of columns in a histogram should have the square root of the sample size -------eg. 100 samples will show 10 bars 1) Normal. A common pattern is the bell-shaped curve known as the "normal distribution." 2) In a normal distribution, points are as likely to occur on one side of the average as on the other. ***Be aware, however, that other distributions look similar to the normal distribution. Statistical calculations must be used to prove a normal distribution.
Historically, the number of flaws in the finish of surface has an average of 0.45. What is the probability of a randomly selected item having more than 1 defect in the surface finish?
Historically, the number of flaws in the finish of surface has an average of 0.45. What is the probability of a randomly selected item having more than 1 defect in the surface finish? Poisson distribution is used to model rates. The probability of r events occuring is computed: P (r) = ( mean ^ r) (e ^ -mean) / ( r !) r= 0 and mean = 0.45 give the probability of exactly zero defects: 0.6376 Entering r=1 and mean= 0.45 give probability of exactly 1 defects: 0.2869 Entering r=2 and mean= 0.45 give probability of exactly 2 defects: 0.6376 + 0.2869 = 0.9245 Probability of more than one defect is 1 - ( 0.9245 ) = 0.0755
Horizontal Communications
Horizontal Communications Information sharing across same levels of the organization----eg. engineers sharing with production planning group
How are Stakeholders impacted with project's stated goals are not met?
How are Stakeholders impacted with project's stated goals are not met? 1) Stockholders ---company's net worth reduced 2) Suppliers---delayed payments and never get full payment 3) Management --Frozen/ diminished wages and reduced staff 4) Customers may impose fines and seek legal action or seek other places to be.
How can a process inputs and outputs be identified?
How can a process inputs and outputs be identified? 1) Process can measured and improved by identifying its inputs and outputs 2) Process inputs can be quantified as raw materials, human resources, or some upstream process. Process input requirements should be stated so key measures of input quality can be controlled. 3) Once process capabilities are known, output measures can be used to determine whether the process has remained in control.
How many individual values are considered sufficeint to accurately calculate the upper and lower control limits of X-bar-R control charts.
How many individual values are considered sufficeint to accurately calculate the upper and lower control limits of X-bar-R control charts. 100 data values
How many non-alue added activities are classified as muda by Imai? A. 4 B. 5 C. 7 D. 9
How many non-alue added activities are classified as muda by Imai? A. 4 B. 5 C. 7 D. 9 C- correct. 7 categories of waste: overproduction, inventory, rejects, motion, additional processing, waiting, & transport
How many of the following Japanese techniques are supportive of operational control? A. Poke-yoke, gemba, 5S, muda b. Poke-yoke and 5S, muda c. TPM, gemba, kanban, 5S d. kanban, poka-yoke, 5s, TPM
How many of the following Japanese techniques are supportive of operational control? A. Poke-yoke, gemba, 5S, muda b. Poke-yoke and 5S, muda c. TPM, gemba, kanban, 5S d. kanban, poka-yoke, 5s, TPM D- Correct--- Poke-yoke controls mistakes, 5S controls organizations, TPM control machines maintenance, Kanban controls workflow.
How to conduct measurement correlation?
How to conduct measurement correlation? 1) Scatter diagram= detection of special causes due to multiple measurement systems 2) Analysis of "components of variation" = use of multiple appraiser and devises with randomized trials ---> If there is a significant P=value in the variance between measurement equipment, then investigate
Hypergeometric Distribution
Hypergeometric Distribution 1) Finite population with N-items that fall into a class of interest. 2) Random sample of n-items is selected from the population WITHOUT REPLACEMENT
Hypothesis Tests for Means: Z-test
Hypothesis Tests for Means: Z-test: 1) When the population follows normal distribution and the population standard deviation is known, then the hypothesis tests for comparing a population mean with a fixed value for mean 2) A statistical test used to determine whether two population means are different when the variances are known and the sample size is large. The test statistic is assumed to have a normal distribution and nuisance parameters such as standard deviation should be known in order for an accurate z-test to be performed.
IDs of a certian peice of tubing are distributed with mean of 1.00. Proportion of tubing with ID's less than 0.9 is:
IDs of a certian peice of tubing are distributed with mean of 1.00. Proportion of tubing with ID's less than 0.9 is: Answer= less than the proportion of IDs greater than 1.0
Identify 2 lean techniques that often used interchangeably: A. Motion study and JIT principles B. SMED and SUR C. TPM and visual displays D. 5S systems and NVA activities
Identify 2 lean techniques that often used interchangeably: A. Motion study and JIT principles B. SMED and SUR C. TPM and visual displays D. 5S systems and NVA activities B-correct ; SUR- setup reduction
Identify a Non-value added activity that wold be considered a form of processing muda? A. All forms of transportation B. Ergonomically unsound workplace C. Reshaping a product due to poor dies D. Producing more than needed by the customer
Identify a Non-value added activity that wold be considered a form of processing muda? A. All forms of transportation B. Ergonomically unsound workplace C. Reshaping a product due to poor dies D. Producing more than needed by the customer C==Correct; D is overproduction muda, B=motion muda; A- transportation muda
Identify the assumption that is made when conducting an experiment: a. that the measurement system is capable for all included responses. b. that the selected factors are the only ones of importance. c. that the process changes radically during the duration of the test. d. that residuals are not important.
Identify the assumption that is made when conducting an experiment: a. that the measurement system is capable for all included responses. b. that the selected factors are the only ones of importance. c. that the process changes radically during the duration of the test. d. that residuals are not important. A= correct B==is the the actual reason that people conduct experiments.
Identify the business element that would directly reduce cycle times? a. Utilizing Problem Solving Tools B. Implementing 5S C. Practicing SMED D. Supervising people
Identify the business element that would directly reduce cycle times? a. Utilizing Problem Solving Tools B. Implementing 5S C. Practicing SMED D. Supervising people C- Correct; SMED= single minute exchange dies
Identify the data conversion that would be most difficult to accomplish: a. attribute data converted to variable data b. variable data converted to attribute data c. Accumulated "go/ no-go" data converted to variables data d. Variables data converted to go/ no-go data
Identify the data conversion that would be most difficult to accomplish: a. attribute data converted to variable data b. variable data converted to attribute data c. Accumulated "go/ no-go" data converted to variables data d. Variables data converted to go/ no-go data C= correct. Variable data can easily be converted to attribute data. Attribute data can be converted to attribute COUNTED data
Identify the distribution that presents the most difficulty in using tables directly to determine either probabilities or critical values: a. Posisson distribution b. Standard normal (z) values c. t-distribution d. binomial distribution
Identify the distribution that presents the most difficulty in using tables directly to determine either probabilities or critical values: a. Posisson distribution b. Standard normal (z) values c. t-distribution d. binomial distribution D= correct; Table for binomial distribution gets volunminous very rapidly. The other 3 options have tables that can provide proabilities or critical values for almost any conditions in one, tow, or three pages.
Identify the element that is associated with excess inventory? A. Storage space and transportation vehicles B. Machine downtime and lack of parts C. Repair and rework D. Poke-yoka devices
Identify the element that is associated with excess inventory? A. Storage space and transportation vehicles B. Machine downtime and lack of parts C. Repair and rework D. Poke-yoka devices A- Correct; (B) - muda of waiting; (C)= muda of rework
Identify the most appropriate lean thinking statement from the options below. a) lean concepts include value, flow, pull, and perfection b) Concentration on customer support c) lean thinking added NVA d) Lean means reducing people
Identify the most appropriate lean thinking statement from the options below. a) lean concepts include value, flow, pull, and perfection b) Concentration on customer support c) lean thinking added NVA d) Lean means reducing people A- correct
Identify the most difficult limitation in achieving continuous flow: A. untrained employees B. existing equipment C. Employee culture D. Middle management involvement
Identify the most difficult limitation in achieving continuous flow: A. untrained employees B. existing equipment C. Employee culture D. Middle management involvement B- correct---All choice except existing equipment can be changed by training and management
Identifying Characteristics to be measured in a process capability study should meet 3 requirements
Identifying Characteristics to be measured in a process capability study should meet 3 requirements: 1) Characteristic should be indicative of a key fctor in the quality of product or process 2) Possible to adjust the value of the characteristic 3) Operating condition that affect the measured characteristic should be defined and controlled. ***When multiple product dimensions, best to select a few key dimension for manageable method of evaluating process capability. -----> may be dtermined by the history of the part and the parameter that has been the most difficult to control OR by problem created in the higher levels of assembly. ***Customer purchase order requirements or industry standards may also determine the characteristics that are required to be measured
Identifying Specification/ Tolerances
Identifying Specification/ Tolerances: 1) Specification/ Tolerances of a process are determined by : a) Customer Requirements b) Industry Standards c) Organization's Engineering Department 2) Process Capability Study------> used to demonstrate that the process is centered within the specification limits and that the process variation predicts the process is capable of producing parts within the tolerance requirements 3) If process is found to be not capable, the then process capability results are used to improve the process 4) If the specifications/ Tolerance too high------> Reevaluate these parameters OR perform 100% inspection of the process, unless inspection testing is destructive.
If 87 data observations from a process were to be plotted on a histogram, the rule of thumb would suggest how many intervals across the range of data?
If 87 data observations from a process were to be plotted on a histogram, the rule of thumb would suggest how many intervals across the range of data? Answer= 9 intervals Rule of Thumb= No. of Data intervals = square root of number of data observations Square root of 87 = 9.32
If X can be any random variable mean (mu) and standard deviation. (n) - random samples. As n increases, and as results of central limit theorem.... what happens to the distribution?
If X can be any random variable mean (mu) and standard deviation. (n) - random samples. As n increases, and as results of central limit theorem.... ---> Distribution of X-bar approaches a normal distribution with a mean (mu) and standard deviation (sigma / square root of n)
If a company were to evaluate why some customer refused to purchase a newly released product, what Deming cycle phase would apply? A. Plan B. Do C. Study D. Act
If a company were to evaluate why some customer refused to purchase a newly released product, what Deming cycle phase would apply? A. Plan B. Do C. Study D. Act C-correct
If a engineer or technician were to select samples from a mixture in a vat that is suspected of separation, what sampling technique would be advisable?
If a engineer or technician were to select samples from a mixture in a vat that is suspected of separation, what sampling technique would be advisable? Stratified sampling because the vat is suspected of not being homogenous.
If a metric were being developed to track marketplace response, which of the following items could be included? A. Cost of quality B. Customer retention C. Cycle time reduction D. Profit margin on sales
If a metric were being developed to track marketplace response, which of the following items could be included? A. Cost of quality <0----measure of resource allocation B. Customer retention --Correct C. Cycle time reduction 0---measure of cost or internal resources. D. Profit margin on sales ---measure of profit B-answer
If a process is out of control, the theoretical probability that a single point on the X-bar chart will fall between one sigma and the UCL: a. 0.2220 b. 0.1587 c. Unknown d. 0.3413
If a process is out of control, the theoretical probability that a single point on the X-bar chart will fall between one sigma and the UCL: a. 0.2220 b. 0.1587 c. Unknown d. 0.3413 C= correct. Tricky question. "out of control" = key phrase If the process were IN CONTROL, a simple Z-value determination would yeild 0.1587 as the correct asnwer.
If events A and B are independent, then: a. P (B/ A) = P (A) b. P ( A/B) = P (B) c. P (B/ A) = P (B) d. P (B/ A) = P (A) + P (B)
If events A and B are independent, then: a. P (B/ A) = P (A) b. P ( A/B) = P (B) c. P (B/ A) = P (B) d. P (B/ A) = P (A) + P (B) Answer= C If 2 events are independent, gaining information about one provides no information about the probability of the other event occurring. Thus, the probability of event B occurring given event A has occurred P (B/A) is the equal to the probability of event B occurring
If events cannot occur simultaneously they are called: a. Randomly selected b. Mutually exclusive c. Independent d. Statistically
If events cannot occur simultaneously they are called: a. Randomly selected b. Mutually exclusive c. Independent d. Statistically B= correct Random selection means that all elements available for selection have the same chance of being chosen. Independent events are those in which the occurrence of one does not affect the probability of the other. A process which yields 8 consecutive values above or below the mean is not considered statistically stable. Events are mutually exclusive if that can't happen at the same time.
If metrics were used to track marketplace response as part of strategic plan deployment, which of the following measures is unlikely to be included? A. Analysis of Returns B. Cost of Quality C. Customer market surveys D. Customer Retention
If metrics were used to track marketplace response as part of strategic plan deployment, which of the following measures is unlikely to be included? A. Analysis of Returns B. Cost of Quality C. Customer market surveys D. Customer Retention B- correct---> Bis a resource measurement (Section II 35-36)
If one chose to look at any business on a mail level basis, which of following categores would be inegrated into other KPIC AND KPOV AREAS? A. process B. Operations C. Business D. Technological
If one chose to look at any business on a mail level basis, which of following categores would be inegrated into other KPIC AND KPOV AREAS? A. process B. Operations C. Business D. Technological D- Correct. --All other answers have key input and output variables---> D is not separately identified and is integrated into 3 categories Section II -34/41
If one is interested in reducing inventory and product lead times, what Japanese control terms would apply?
If one is interested in reducing inventory and product lead times, what Japanese control terms would apply? Heijunka! ---means leveling of the production--this in turn, reduce inventory and lead times
If one were to compare short-term capability with long-term capability for the same process, what would be observed?
If one were to compare short-term capability with long-term capability for the same process, what would be observed? Short-term Cp is better Both the average and the variability changes over time
If one were to summarize in one word the ground breaking work of Womack, in introducing the lean production to the West, it would: a. muda b. value c. distance d. rhythm
If one were to summarize in one word the ground breaking work of Womack, in introducing the lean production to the West, it would: a. muda b. value c. distance d. rhythm b-correct
If process improvement ideas have been submitted for project selection. Unknown to the team, two of these ideas have the potential for breakthrough improvement. If your team selects 2 projects at random, what is the chance of picking both winners?
If process improvement ideas have been submitted for project selection. Unknown to the team, two of these ideas have the potential for breakthrough improvement. If your team selects 2 projects at random, what is the chance of picking both winners? Answer= 0.0095 P ( A ∩ B) = (2/ 15) (1/ 14) = 2/ 210 = 0.0095
If six consecutive samples were taken from a process and measured precisely, one would still expect to find differences. What type of variation would be most difficult to determine?
If six consecutive samples were taken from a process and measured precisely, one would still expect to find differences. What type of variation would be most difficult to determine? Lot-to- lot variation (not inherent variation) Small sample size would make it impossible to provide a high level of confidence in the results. However, measurement error, inherent process variation and piece-to-piece variation obtainable
If specification limits are wider than control limits, then : a. process is capable b. process capability index greater than 1.0 c. specification limits replace the control limits on chart d. none of above
If specification limits are wider than control limits, then : a. process is capable b. process capability index greater than 1.0 c. specification limits replace the control limits on chart d. none of above D= correct; No conclusion can be draw if sample size is unknown. ---see the formula for process capability which requests for sample size
If the probability of success on a single trial is 0.3 and two trials are performed, what is the probability of at least one success?
If the probability of success on a single trial is 0.3 and two trials are performed, what is the probability of at least one success? VII- 14/15 P= 0.3 P(r) = C ( 1-0) Classical binomial problem since the number of trials is small and probability is greater than 10%.....the above formula can be solved for zero occurrences and subtracted from one. Use the binomial table where the answer for zero occurences is listed as 0.490. Subtracting the value from 1 gives you 0.520 Sectin VII- 14/15
If the variance of a distribution of readings is 16. the standard deviation of the distribution is: ?
If the variance of a distribution of readings is 16. the standard deviation of the distribution is: ? S= Square root (variance) = Square root of 16= 4
Implementation of a control plan in the painting department was so successful that a master black belt wants you to implement the same control plan in the final assembly line. What changes should be made before implementing the necessary control plan? a. Each control plan is unique, a new plan must be developed for the final assembly line b. A lot of changes will be necessary. c. No changes are needed, since the two areas are in the same company d. Minor chnages may be necessary to relect the assembly line differences
Implementation of a control plan in the painting department was so successful that a master black belt wants you to implement the same control plan in the final assembly line. What changes should be made before implementing the necessary control plan? a. Each control plan is unique, a new plan must be developed for the final assembly line b. A lot of changes will be necessary. c. No changes are needed, since the two areas are in the same company d. Minor chnages may be necessary to relect the assembly line differences A= correct Each part of process must have a control plan and each plan is unique. Common parts using a common process can share a single control plan. In this case, it is obvious that the painting department and the finaly assembly line are completely different, calling for totally different control plans. Many changes are required to create the final assembly line control plan. However, a new control plan must be developed
In Japanese and American system, the flow of material is control by ......??
In Japanese and American system, the flow of material is control by ......?? Kanban cards
In Placket- Burman geometric designs, one would expect: a. that each interaction effect is confounded with 2 main effects b. that each interaction effect would not be confounded c. that only pure main effects will be determined d. that each interaction effect will be confounded with exactly one main effect
In Placket- Burman geometric designs, one would expect: a. that each interaction effect is confounded with 2 main effects b. that each interaction effect would not be confounded c. that only pure main effects will be determined d. that each interaction effect will be confounded with exactly one main effect D= correct PB geometric design have interaction effects confounded with exactly one main effect Non-geometric PB, 2 -factor interactions will be partially confounded with each of the other main effects.
In a full factorial experiment with 4 factors and 3 levels, how many trials are required?
In a full factorial experiment with 4 factors and 3 levels, how many trials are required? Answer= 81 No. of required trials = (#of levels) ^ (No. of factors) 3 ^4 =81
In a hypothetical situation, if all within time, piece-to-piece, and measurement variation were removed from a process, what would be left?
In a hypothetical situation, if all within time, piece-to-piece, and measurement variation were removed from a process, what would be left? Inherent process variation
In a new product design, the "fuzzy front end" refers to: A. Idea generation and sorting idea B. Sorting of ideas and concepts C. conducting feasibility studies D. Continuous learning techniques
In a new product design, the "fuzzy front end" refers to: A. Idea generation and sorting idea B. Sorting of ideas and concepts C. conducting feasibility studies D. Continuous learning techniques A- Correct (Section III-21) and XI-page 4
In a nutshell, six sigma is considered: A. Business improvement approach B. Focus on critical customer items C. Elimination of mistakes and defect D. Concentrated focus on business outputs.
In a nutshell, six sigma is considered: A. Business improvement approach B. Focus on critical customer items C. Elimination of mistakes and defect D. Concentrated focus on business outputs. A= best answer
In a production factory, which utilizes the pull system, which of the following may be achieved? A. Expand raw material inventory B. Reduced in-process inventory C. Increased prices D. Increased finished good inventory
In a production factory, which utilizes the pull system, which of the following may be achieved? A. Expand raw material inventory B. Reduced in-process inventory C. Increased prices D. Increased finished good inventory B- correct; Pull system is driven by customer demand; Stabilized prizes and increased profits can be achieved
In determining a process average fraction defective using inductive or inferential statistics, which of the following would be used. a. Statistics, computed from samples, to to make inferences about populations b. Populations, computed from samples, to to make inferences about populations c. Samples, computed from statistics ,to to make inferences about populations d. Samples, computed from populations, to to make inferences about populations
In determining a process average fraction defective using inductive or inferential statistics, which of the following would be used. a. Statistics, computed from samples, to to make inferences about populations b. Populations, computed from samples, to to make inferences about populations c. Samples, computed from statistics ,to to make inferences about populations d. Samples, computed from populations, to to make inferences about populations A= correct Question requires the review of answer options. In inferential stations, one is always making inferences about the populations. From the wording of the question, statistics computed from samples is a more logical choice.
In highly effective six sigma companies, most employee receive some training. What group is most likely to receive sponsorship training? A. Senior management B. Master belt C. Black Belt D. Green belt
In highly effective six sigma companies, most employee receive some training. What group is most likely to receive sponsorship training? A. Senior management B. Master belt C. Black Belt D. Green belt A. ---correct
In most cases, data should be collected in: a. statistical cormat b. Homoenous layers c. Time sequence.
In most cases, data should be collected in: Homogenous layers
In normal distribution, what is the area under the curve between 0.7 and 1.3 standard deviation units?
In normal distribution, what is the area under the curve between 0.7 and 1.3 standard deviation units? Z-value of o.7 and 1.3 must be looked up. 0.242 - 0.0968 = 0.1452
In order to arrange machines and operations into a tight sequence, a wok cell designed to satisfy lean principles would typically: A. Have circle shape B. Be a straight line C. Have a batch queue setup d. Have U or L shape
In order to arrange machines and operations into a tight sequence, a wok cell designed to satisfy lean principles would typically: A. Have circle shape B. Be a straight line C. Have a batch queue setup d. Have U or L shape D- correct
In order to calculate a performance index, what two factors must be known about the process?
In order to calculate a performance index, what two factors must be known about the process? Answer= Specification limits and standard deviation . Calculation of Performance Index: Pp = ( USL - LSL) / 6 *Sigam
In performing an analytical study, Which of the following statistical values would seldom be known? a. true critical value b. sample statistic c. true population parameter d. degree of uncertainty.
In performing an analytical study, Which of the following statistical values would seldom be known? a. true critical value b. sample statistic c. true population parameter d. degree of uncertainty. C= correct Person doing the analytical study would use sample statistic for comparison against the critical value for a predetermined degree of risk.
In the control stage of DMAIC, critical stains have been reduced from 73 to 1 per fabric roll. Which control chart should be used?
In the control stage of DMAIC, critical stains have been reduced from 73 to 1 per fabric roll. Which control chart should be used? Control chart based on Poisson distribution such as u-chart. Critical stains are defect counts which describes Poisson distribution
In the long run, who/what defines the value of a product or service? A. Customer B. Upper management C. Cost and related expenses D. Amount of accrued muda
In the long run, who/what defines the value of a product or service? A. Customer B. Upper management C. Cost and related expenses D. Amount of accrued muda A- Correct
In what areas would upper management be most helpful in the initiation of 6 sigma effort. A. Providing direct training to black belts B.Standardizing business operations C. Providing key resources to the organization D. Directing the improvement projects
In what areas would upper management be most helpful in the initiation of 6 sigma effort. A. Providing direct training to black belts B.Standardizing business operations C. Providing key resources to the organization D. Directing the improvement projects C= correct---Upper management functions best by providing overall direction and resources. Section 11- pg 16
In which situation is the use of X-bar and R-chart likely to be most helpful as a tool to control process: a. machine capability is wider than specification b. machine capability is equal to specification c. machine capability is somewhat smaller than specification d, machine capability is small compared to specification
In which situation is the use of X-bar and R-chart likely to be most helpful as a tool to control process: a. machine capability is wider than specification b. machine capability is equal to specification c. machine capability is somewhat smaller than specification d, machine capability is small compared to specification C= correct Control chart not useful if capability is wider than specification
Increasing a performance in 6sigma corporation from 3 sigma to 4 sigma would reduce DPM by a factor of A. 2 B. 8 C. 10 D. 16
Increasing a performance in 6sigma corporation from 3 sigma to 4 sigma would reduce DPM by a factor of A. 2 B. 8 C. 10 D. 16 C= correct---> Since 6sigma is referenece, then assume that +/- 1.5 sigma must be included. Using the shift, the 4 sigma defect rate is 6,210 ppm and 3 sigma rate is 66,810 ppm or a ratio of 1: 10.76 Section II-3
Which Inference Test? Two sample means. Variances unknown, but considered NOT equal
Independent t-test (unpaired) Two sample means. Variances unknown, but considered NOT equal
Inferences in Simple Regression
Inferences in Regression 1) Sample data used to calculate the b(i) s coifficient (b-values from sample) 2) Must determine the closeness of the calculated b-values to the actual coefficient values for the population. ---> Accuracy of approximations depends on sampling error. 3) Assume that the means of these distributions lie in a straight line whole equation is y=B(o) + B (i) x and that the distributions are normal with equal standard deviations (sigma) 4) Sample means [b(0) & b(i)] used to estimate the population means (Bo and Bi)
When t0 use Inter-relationship Digraphs/ Relations Diagram
Inter-relationship Digraph ====Visual display that maps out the cause and effect links among complex, multivariable problems or desired outcomes. It helps the team to analyze the natural links between different aspects of a complex situation. A Inter-relationship Digraphs used for: a) When trying to understand links between ideas or cause-and-effect relationships, such as when trying to identify an area of greatest impact for improvement. b) When a complex issue is being analyzed for causes. c) When a complex solution is being implemented. d) After generating an affinity diagram, cause-and-effect diagram or tree diagram, to more completely explore the relations of ideas.
Interaction term in an R & R ANOVA indicates interaction between?
Interaction term in an R & R ANOVA indicates interaction between? Technician and part (Not technician and measurement error)
Internal Failure Costs
Internal Failure Costs 1) Employee Turnover 2) Late Time cards 3) Overpayments 4) Rework/Redesign/ Retyping letters/ Rework 5) Sorting/ Scrap 6) Excess inventory/ material handling/ interest expense/ travel expense
Interpreting Gage R&R Report
Interpreting Gage R&R Report 1) EV (equipment variation)= standard deviation of repeatability [sigma (rat)] 2) AV= (apprasair variation ) = standard deviation of reproducibility [sigma (rpd)] 3) GRR= standard deviation of measurement system variation[sigma (M)] 4) PV= standard deviation of part-to-part variation [sigma (p)]
How to interpret Run Charts?
Interpreting Run Charts: 1) Subgroup= 1--> use run charts 2) Subgroups greater 1 ---> calculate the means or medians and connected with a line.
Data arranged in order and differences can be found. There is no inherent starting point and ratios are meaningless
Interval Data Data arranged in order and differences can be found. There is no inherent starting point and ratios are meaningless
Interval Estimate
Interval Estimate In statistics, interval estimation is the use of sample data to calculate an interval of possible (or probable) values of an unknown population parameter, in contrast to point estimation, which is a single number. It is the interval within which the population mean is predicted to fall
Interval estimate
Interval estimate: Interval within which the population mean is predicted to fall or the population parameters derived from the mean and standard deviation. **Confidence interval is a two-tail event and requires critical values based on (alph/2) risk **Central limit thereom term (sigma / sq. root of sample size) is necessary b/c CU is the populaiton mean and not the individual values.
Is the Process Acceptable? Ppk (Capability)
Is the Process Acceptable? Ppk (Capability) Ppk is another performance index that measures how close the current process mean's proximity is to the specification limits. In other words, does this process deliver acceptable results?
When is Cpk used?
It is an option (along with Z-score and PPM) when describing process baseline measurement in the MEASURE phase or in the CONTROL phase when obtaining the final performance analysis. As with all the process capability indices, the process should be in control before assessing capability.
It is suspected that a process requiring a capability determination is not normal, but appears to be stable. The last action to , at this point would be to: a.advise the customer and request specification changes b. reduce variation to the point that it doesn't matter c. transform data to that of a normal distribution d. test the normality assumption using a chi-square test.
It is suspected that a process requiring a capability determination is not normal, but appears to be stable. The last action to , at this point would be to: a.advise the customer and request specification changes b. reduce variation to the point that it doesn't matter c. transform data to that of a normal distribution d. test the normality assumption using a chi-square test. A= correct. (B) is expenseive
JIT is characterized by: a. producing the right items at the right time b. delivering the right items early c. producing the right amounts using multi-piece flow d. delivering the right time considering company priorities
JIT is characterized by: a. producing the right items at the right time b. delivering the right items early c. producing the right amounts using multi-piece flow d. delivering the right time considering company priorities A- correct
Juran & 3 dimension of measuring process quality
Juran & 3 dimension of measuring process quality 1) Effectiveness= how well the output meets the customer needs. 2) Efficiency = the ability to be effective , at the lowest cost. 3) Adaptability= the ability to remain effective and efficient in the face of change ***These measurements address the need for business processes to provide value to both customer (effectiveness) and shareholders (efficiency), now and in the future (adaptability) . Six Sigma tries to manage ENTIRE business process the maximize the business process goals for the OVERALL business.
Kano Model
Kano Model Analsysis 1) Used to Analyze Customer Requirements 2) Based on 3 categories: a) Dissatisfiers or "Must Be's "------> customer expects that basic requirements are part of the basic package (eg. steering wheel in car) b) Satisfiers or "More is Better" ----> when these requirements are met, the more it is met then the better (eg. Tourist on a cruise expect personal attention) c) Delighters----> services/features that go beyond expectations. ***Improvement projects are selected among the satisfier and delighter categoreis.
Kaplan and Norton have outlined a business planning process that gives consideration to factors other than strictly financial ones. It provides a greater perspective to the stakeholder interest. This approach is referred to as: A. Balanced Scorecard B. Strategic Planning C. Fiver Forces of Competitive Strategy D. Quality Function Deployment
Kaplan and Norton have outlined a business planning process that gives consideration to factors other than strictly financial ones. It provides a greater perspective to the stakeholder interest. This approach is referred to as: A. Balanced Scorecard B. Strategic Planning C. Five Forces of Competitive Strategy D. Quality Function Deployment Answer= A--balanced scorecard QFD is the House of Quality
Key points for Process Identification
Key points for Process Identification 1) Processes affect multiple departments 2) Cross-functional areas and organizations can challenge improvement projects and should be understood to define the process. 3) SIPOC diagram used to identify these functional areas and organizations affecting the process 4) Flow chart and process map=other tools
Key reason for conducting ongoing measurement system analysis?
Key reason for conducting ongoing measurement system analysis? To understand the uncertainty of the measurement system.
Labor Cost Bases: Two Types
Labor Cost Bases: Two Types 1) Total direct Labor (worked) 2) Standard Labor (planned)
Lean enterprise can be summarized as: A. Enterprise organization involved with improvement B. Implementation of SMED cycle time techniques C. Poke-yoke techniques in action D. Ergonomic principles in the workplace
Lean enterprise can be summarized as: A. Enterprise organization involved with improvement B. Implementation of SMED cycle time techniques C. Poke-yoke techniques in action D. Ergonomic principles in the workplace A- Correct
Lean manufacturing would be most concerned with: a. reducing waste and elimination of bottlenecks b. reducing people and waste c. reducing management and reducing people d. eliminating bottlenecks and reducing management layers
Lean manufacturing would be most concerned with: a. reducing waste and elimination of bottlenecks b. reducing people and waste c. reducing management and reducing people d. eliminating bottlenecks and reducing management layers A- correct
Lean thinking enables companies to: a practice kanban techniques b. identify the value stream for each product and reduce waste c. push product through the system d. maximize throughput
Lean thinking enables companies to: a practice kanban techniques b. identify the value stream for each product and reduce waste c. push product through the system d. maximize throughput B- correct
Least Squares Method
Least Squares Method Statistical procedure of finding the "best fitting" straight line that minimizes the sum of squares of deviations of the observed values of Y from those predicted.
Lessons Learned
Lessons Learned 1) Formal and documented critique that analysize what went well or wrong to use in future projects. 2) Conducted by committee of qualified persons 3) C overs all phases of Development Topics: a) Project tracking, recognition of project team efforts, project team performance, cooperation amongst team members, quality level of end product/service, effectiveness of corrective actions, and adequacy of resources.
Limitations of Quality Cost System
Limitations of Quality Cost System 1) Quality cost measurements don't solve quality problems 2) Quality cost reports don't suggest specific actions 3) quality cost are prone to short-term mismanagement 4) Difficult to match effots with accomplishments 5) Omission of important costs from quality cost reports 6) Inappropriate costs may be included in cost reports 7) Quality cost may have measurement errors
Linearity
Linearity 1) Found by obtaining reference part measurement values throughout the operating range of the instrument and plotting the bias against the reference values. 2) Default procedure for determining linearity is to measure 10 parts 5 times. 3) % linearity = slope -----> Linearity is equal to the slope multiplied by the process variation (process spread or tolerance)
Accuracy of measurement at various measurement points of measuring range in the equipment
Linearity Accuracy of measurement at various measurement points of measuring range in the equipment
Linearity & bias in Gauge R& R
Linearity & bias--Measures of Accuracy Linearity: a measure of how the size of the part affects the bias of a measurement system. It is the difference in the observed bias values through the expected range of measurement. 1) Equipment is accurate at one point of measurement but not at other point of measurement across the measurement range. 2) How biased the measuring equipment is compared to the "master" 3) If R-sq = 0.0% ---> Non-linearity
Scatter Diagrams--Linearity and Implications
Linearity and Implications 1) Judges the possibility that bias error found in particular system of measurement will be present throughout the equipment's entire operating range. 2) Measure Stage---> Assessing the accuracy of a measurement system within the range of values likely to be observed during the process. 3) Procedure for analysis of linearity ---> Operating range is examined in multiple parts and then reference value is obtained---> An average of the ranges is calculated after repeated measurements taken----> Bias is calculated by subtracting the average from reference value. ----> Coiffiecient of determination of greater than 70% will mean that measurements are adequate.
List 4 reasons that Pareto diagram are used
List 4 reasons that Pareto diagram are used: 1) Analyze a problem from a new perspective 2) Focus attention on problems in priority order 3) Compare Data changes during different time periods 4)Basis for construction of a cumulative line ***Cumulative lines help answer questions like "What defect classes constitute 70% of all defect?"
Listed below are some of the most widely recognized forms of muda or NVA. Which two would not result in poor product quality? a. Overproduction and inventory b. Repair/reject and processing c. motion and waiting d. Processing and transport
Listed below are some of the most widely recognized forms of muda or NVA. Which two would not result in poor product quality? a. Overproduction and inventory b. Repair/reject and processing c. motion and waiting d. Processing and transport
Locational Data
Locational Data 1) Not attribute or variable data 2) Tells about location 3) Eg. Map of USA with sales area or map of all the Walmarts in the USA.
Lognormal Distribution
Lognormal Distribution Basic assumptions: Asymmetrical and positively skewed distribution that is constrained by zero. Distribution can exhibit many pdf shapes Describes data that has a large range of values Can be characterized by m and s
Long-term Capability
Long-term capability indices (PP and PPK): The same capability indices that you calculate for short-term variation can also be calculated for long-term, or total, variation. To differentiate them from their short-term counterparts, these long-term capability indices are called PP and PPK. (The P stands for "performance.") The only difference in their formulas is that you use σLT in place of σST. These long-term capability indices are important because no process or characteristic operates in just the short term. Every process extends out over time to create long-term performance.
How would one determine the ppm failure rate for normal distribution?
Look it up in a table such as standard normal table or six sigma failure rate
Machine Capability
Machine Capability 1) Short-term capability measurement that is used to determine the inherent process (machine variation) by EXCLUDING elements like batch-to-batch, stream-to-stream, and time-to-time variation and by MINIMIZING measurement factors (operator & equipment), piece-to-piece variation, and within piece variation. 2) Control charts can be used to determine machine capability if the process is free of drift, depending on how the information will be used for improvement
Machine Capability- Exceptions
Machine Capability 1) Short-term capability of a machine and calculated the same as process capability except: a) Historical data from control chart not to be used b) Multiple machines producing the same part ---> capability of machine should be determined independently. c) Machine capability should come from consecutive part measurements from same machine at or near the same time
Define machine capability
Machine Capability = the inherent variation of the machine
Main Objective of the Measure State
Main Objective of the Measure State: 1) Data gathering to complete project. 2) Team defines each relevant process in great detail. 3) Group of metrics for the process is developed 4) Measurement analysis is conducted to identify and quantify any common errors in the metric that is selected. 5) Estimation of process baselines to determine a reasonable starting point.
Main advantage of Quality function deployment
Main advantage of Quality function deployment: Without QFD system that uses data to effect changes, the best customer data collection and analysis is useless. QFD system studies each item of customer feedback to determine which processes, products, and /or services will be impacted and also tells the volume and urgency of the customer needs.
Main objective of process capability study
Main objective of process capability study To determine whether process is in statistical control is is capable of meeting specifications.
Main purpose of Gage R & R is?
Main purpose of Gage R & R is? To determine how much of the total variation is due to measurement errors
Maintaining extra copies of instructional information in description of which NVA? A. Overproduction B. Inventory C. Processing D. Transport
Maintaining extra copies of instructional information in description of which NVA? A. Overproduction B. Inventory C. Processing D. Transport C- correct
Manufacturer of children's wagaons would like to visualize where the defects occur on the wagons. Defects encountered so far include missing bolts, paint, peeling, missing decals, cracked wood, bent metal parts. A useful tool would be: a. X Y matrix b. Measles chart c. Regression Plot d. Scatter diagram
Manufacturer of children's wagaons would like to visualize where the defects occur on the wagons. Defects encountered so far include missing bolts, paint, peeling, missing decals, cracked wood, bent metal parts. A useful tool would be: a. X Y matrix b. Measles chart c. Regression Plot d. Scatter diagram B= Measles cahrt
Manufacturer of micro tubing measures a single unit width in 4 different locations. For every unit measured, the 4 readings become one sample. The sample mean and range are then plotted on a X-bar and R chart. The result chart shows a distinct lack of control. How would you interpret the results. a. look for assignable causes of variation b. look for chance causes of variation c. Combination of chance and assignable causes of variation d. The approach is inconsistent with rational sub-grouping, make the charts meaningless.
Manufacturer of micro tubing measures a single unit width in 4 different locations. For every unit measured, the 4 readings become one sample. The sample mean and range are then plotted on a X-bar and R chart. The result chart shows a distinct lack of control. How would you interpret the results. a. look for assignable causes of variation b. look for chance causes of variation c. Combination of chance and assignable causes of variation d. The approach is inconsistent with rational sub-grouping, make the charts meaningless. D= correct. The 4 readings will explain part positional variation, but may confuse both chance and assignable variation. The resulting chart could indicate a state of statistical control or total lack of it, depending upon whether the maximum variations is contained with part or over time. In either case, this is a wrong application. The way to control this process is to measure 4 pieces in teh same locaiton and combine the 4 readings into one sample
Manufacturing cost of output:
Manufacturing cost of output: 1) Total shop cost to output 2) Production engineering costs and expenses 3) Provision for complaints 4) Pakcing and shipping
Marketplace Response is an Performance Measure
Marketplace Response is an Performance Measure: 1) Marketplace response is an organizational performance measure 2) Ability to respond to competitors quality , technology, product, design, safe are all important
Matrix Diagram
Matrix Diagram 1) Used to show the relationship between objectives and methods, results and causes, tasks and people, ect. 2) Must determine the strength of the relationships. 3) Result of two or more tree diagrams can be meshed into matrix
Measure for central location for nominal scale is called?
Measure for central location for nominal scale is called? Mode B/c the nominal scale is a very low level statistic
Measurement Correlation
Measurement Correlation 1) Used when measurement are taken simultaneously with multiple devices of the same type for part coming from multiple streams of manufacturing (eg. instrument calibration)
Measurement Correlation
Measurement Correlation 1) Comparison of measurement values from one measurement system with the corresponding values reported by one or more different measurement systems 2) Both measurement system and standards have variation in their measured value. ---eg. calibration of instruments
Measurement Scales----Ratio
Measurement Scales----Ratio ) Central location = Geometric or Harmonic Mean (both are not the same thing) 2) Dispersion of Percent Variation 3) Significance Test= Any Test 4) Data consists of names or categories without any ordering scheme
Measurement Scales---Interval
Measurement Scales---Interval ) Central location = Arithmetic Mean 2) Dispersion of Standard Deviation 3) Significance Test= F-test, t-test, Correlation Analysis 4) Data is arranged in order and differences can be found. However, there is no inherent starting point and ratios are meaningless.
Measurement Scales---Nominal
Measurement Scales---Nominal 1) Central location = Mode 2) Dispersion of Information only 3) Significance Test= Chi-Square 4) Data consists of names or categories without any ordering scheme
Measurement Scales---Ordinal Data
Measurement Scales---Ordinal Data ) Central location = Median 2) Dispersion of Percentages 3) Significance Test= Sign or Run Test 4) Data arranged in some order but difference between values cannot be determined or are meaningless
Measurement of Project Activity
Measurement of Project Activity 1) Upper management will require scheduling briefing session that can range in depth from project milestones to comprehensive reports.
Why is measurement system discrimination important?
Measurement system discrimination Ability to detect changes in the measured characteristic--important to be able to measure process variation and quantify value (eg. mean) of individual parts.
Measures of Central Tendency
Measures of Central Tendency Different ways of characterizing the central value of a collection of data includes-------> Mean, Mode, Median Central Limit Theorem----> Probability distribution of the sample means approach normal distribution as the number of sample sizes increases, provided that they are simple random samples of uniform size.---> used for small sample sizes and when true distribution is unknown
Measuring Project's Success or Failure
Measuring Project's Success or Failure 1) Were the specified goals & objectives achieved 2) Within deadlines 3) At or below cost constraints 4) Utilization of allocated resources *** A project that accomplishes a large feat would still be a success irrespective of delays, over-budget, or failing to meet stated goals
Metrics Selection & 9 dimensions of Quality Measurement
Metrics Selection & 9 dimensions of Quality Measurement 1) Performance ---> Product's primary features 2) Features ----> Secondary features added to the product 3) Conformance ---> product that meets fit, form, & function 4) Reliability------> Dynamic quality of product over time 5) Durability ---> useful life 6) Service -------> Ease of repair 7) Response------> Human Interface 8) Aesthetics ----> Product appearance 9) Reputation----> Based on past performance
Metrics Selection----Primary Metrics
Metrics Selection----Primary Metrics 1) Primary metrics that are considered in project come from several sources (suppliers, customers, internal process) 2) These basic metrics include quality, cycle time, cost, value, and labor
Metrics Selection--- Measurements important in the Marketplace
Metrics Selection---Measurement important in the Marketplace 1) Price / Demand Increases 2) Product Range/Brand name/ Design/ Color Range 3) Conformance Quality 4) Reliability of delivery / Delivery Speed 5) Technical Support/ After-sales Support
Metrics Selection--5 Secondary Metrics
Metrics Selection--Secondary Metrics 1) DPU 2) DPMO 3) Average age of receivables 4) Lines of error free software code 5) Reduction in Scrap
Metrics of the effectiveness of strategic quality plan include" A. DMAIC B. Customer Satisfaction C. CSI number D. Drennik index
Metrics of the effectiveness of strategic quality plan include" A. DMAIC B. Customer Satisfaction C. CSI number D. Drennik index B--correct---> Customer satisfaction, customer retention, warranty claims, number of completed quality project teams are all strategic metrics. CSI can be customer satifaction index or crimse scene investigation. D- madeup
Milestones Reporting
Milestones Reporting 1) Milestones = key points in which plans are to completed 2) Intermediate Milestones= refocus on longer objectives and updates project's current status 3) Project team leader presents the milestones to the management -----includes project status relative to milestone, upcoming roadblock to timely completion, and plans to handle the roadblocks 4) After being approved, milestones are not subject to negotiation or change
Milestones/ Deliverables
Milestones/ Deliverables 1) Initial Team Project should be at 120 days. 2) Only half of the project would include define and measure stages 3) Lower success if the initial project exceeds 160 days
Modifying or Redesigning a product would most likely occur during which two of the PDCA phases A. Plan and Do B. Check and Act C. Do and Act D. Plan and Act
Modifying or Redesigning a product would most likely occur during which two of the PDCA phases A. Plan and Do B. Check and Act C. Do and Act D. Plan and Act C= correct ---> Question suggest that actual work on the design on the design is takin gplace.
Most accurate methods of quantifying Gage R& R?
Most accurate methods of quantifying Gage R& R? ANOVa
Most difficult type of variability to reduce via control charting and/or other techniques is _______?
Most difficult type of variability to reduce via control charting and/or other techniques is _______? Inherent error of measuremnt
Most experts content that the most neglected phase of the DMAIC improvement process is .....?
Most experts content that the most neglected phase of the DMAIC improvement process is .....? Control phase
Most fire hydrants in U.S. have a pentagon shaped head on the valve stem. Primary reason is that the head is not a square or pentagon is A. to encourage the sale of the specialize wrenches for operation B. Mistake proofing so only proper authorities can turn on the water C. From a patent by Fredrick Gaff in 1801 in Philadelphia D. Indicating opering the valve is clockwise rotation.
Most fire hydrants in U.S. have a pentagon shaped head on the valve stem. Primary reason is that the head is not a square or pentagon is A. to encourage the sale of the specialize wrenches for operation B. Mistake proofing so only proper authorities can turn on the water C. From a patent by Fredrick Gaff in 1801 in Philadelphia D. Indicating opering the valve is clockwise rotation. B= correct C is true but does not answer the questio.
Most important element in six sigma deployment is considered: A. Training B. Organizational Structure C. Management Support D. Reward and Recognizition
Most important element in six sigma deployment is considered: A. Training B. Organizational Structure C. Management Support D. Reward and Recognisition Answer C= All of the answer choices are key six sigma elements. However, the question states the "most important element". All other choices can be provided or adjusted if management support is there
Most significant difference between the six step DMADOV design process and the 4 step IDOV design process: A) 2 additional design steps in the DMADOV process B) IDOV uses validate and DMODOV uses verify C) IDOV process is quicker D) IDOV includes measure and analyze in the design step
Most significant difference between the six step DMADOV design process and the 4 step IDOV design process: A) 2 additional design steps in the DMADOV process B) IDOV uses validate and DMODOV uses verify C) IDOV process is quicker D) IDOV includes measure and analyze in the design step D-correct ---A and B are true but not significant. IDOV combines the measure step into identify and design step and also include the analyze step with the design step ( III--pg 25/26)
What is the most valid method for collecting customer data?
Most valid method for collecting customer data? Randomly select a large group of customers and get a compete and accurate data on each one selected. ***Data should be free of bias and should be derived from several different resources. Data accuracy should be verified.
Most widespread use of F distribution?
Most widespread use of F distribution? To test for equality of variances from 2 normal populations
Multi-vari Studies
Multi-vari Studies 1) A multi-vari chart is a tool that graphically displays patterns of variation. It is used to identify possible Xs or families of variation, such as variation within a subgroup, between subgroups, or over time 2) Unlike Stem-and-leaf charts, histograms, and frequency distributions which are snapshots of process variation and tell you nothing about the source of variation, the multivari tool shows you variation (the enemy!!!) by separating it into three possible sources (within-piece, piece-to-piece, and time-to-time.) 3) Used to study 3 types of variation: a) Variation within subgroup b) Variation between subgroups c) Variation over time 4) Used to also investigate the stability or consistency of a process. 5) Interpretation of Muti-vari Studies: a) Length of line =Variation within samples b) Vertical position of lines = variation from sample to sample c) Line connecting the midpoint values helps to identify trends.
Multi-variant Studies analyzes 3 types of variations:
Multi-variant Studies analyzes 3 types of variations: 1) Positional variation 2) Cyclical Variation 3) Temporal Variation
Multiple Linear Regression
Multiple Linear Regression: Extension of the methodology for linear regression to more than one independent variable. By including more than one independent variable, a higher proportion of the variation in y may be explained
Multiple Regression ---1st order and higher order
Multiple Regression ---1st order and higher order 1) First Order---->value of the dependent variable is influenced by each factor by itself as well as combination of 2 factors----> Produces a straight line over small regions so best used for only targeted data (flexing of the plan is due to impact of interacting factors) 2) Higher-Order -----> Includes squares and cubes of the value which produce a response surface with peaks and valleys-----> best for defining the area AROUND the stationary point and for evaluating how current operating parameters influence the response.
Negative Team Dynamic: Attribution
Negative Team Dynamic: Attribution 1) Members make cause references (2) Members don't seek explanations, preferring psychological and emotional judgements.
Negative Team Dynamics-- Countermeasures for Digressions & Tangents
Negative Team Dynamics-- Countermeasures for Digressions & Tangents 1) Enforce compliance to agenda items and time allotment 2) Restate the meeting ground rules 3) Redirect the discussions
Negative Team Dynamics-- Digressions & Tangents
Negative Team Dynamics-- Digressions & Tangents: 1) Discussions straying out of scope / agenda of the meetings 2) Distractions 3) Meeting time not properly utilized 4) Not much achieved from meetings
Negative Team Dynamics--> Countermeasures for Discounts
Negative Team Dynamics--> Countermeasures for Discounts 1) Encourage mutual respect 2) Enforce discipline 3) Ask for clarification from members providing opinions
Negative Team Dynamics--> Signs of Discounts
Negative Team Dynamics--> Signs of Discounts 1) Member opinions ignored 2) Members don't listen to each other 3) Sarcasm & low team morale
Nelson Funnel Experiment
Nelson Funnel Experiment 1) While the intent of making small changes to a process may be to make improvements, these perturbations generally increase the variation of the results. To improve a process requires understanding the source of the variation and often controlled experiments to identify process improvements. 2) Equipment operators often 'tweak' the process with the intent to improve yield or throughput. When these adjustment are made without effective feedback system they generally simply increase the variation and chance of failures. 3) No adjustments------> Common cause variation of the system. ---->if we meddle with the process we generally increase the variation. There is a 50% chance that the next drop would have been naturally to the left of the target, so adding a funnel movement would increase the miss to the left. 4) Adjusting to the Target ------> Another cause of this type of variation is managers tampering with worker performance without investing in systemic process changes. Exhorting employees to hit the target more often increases the incidence of meddling with the process. 5) Adusting for " Windage" --->Another way teams increase the variability of a system is to adjust for 'windage'. Windage is the compensation for expected direction of variation. It tends to over compensate and broaden the variation. Examples of the windage adjustments include the US tax policy or corporate right sizing efforts. For item creation windage adjustment occur when using uncorrelated readings to make adjustments for a lot of material, for example. 5) Drift/ Using last run as a guide----This occurs when one operator trains the next operator, who then trains the next, and so on. Another source is not correcting for wear or accumulation often due to ineffective feedback of the process performance.
Nelson Funnel
Nelson Funnel Experiment (Deming) 1) Describes the adverse effects of tampering with a process by making changes to it without first making a careful study of the possible causes of the variation in that process. 2) Marble is dropped through a funnel onto a sheet of paper, which contains a target. The objective of the process is to get the marble to come to a stop as close to the target as possible. ---> Efforts to adjust the marble to hit the mark increase, variation increases.
PERT Network Planning Rules
Network Planning Rules 1) Must complete current activity before starting new one 2) Arrows= logical precendency (length and compass direction of arrow meaningless) 3) Must have unique event numbers 4) Any 2 events may be directly connected only by one activity 5) Network must start at single event and end at the single event. 6) Event numbers must be unique 7) Net
Data consisting of names or categories only. No ordering scheme is possible
Nominal Data Data consisting of names or categories only. No ordering scheme is possible
Which Measurement Scale? Central Location is mode
Nominal Data Central Location is mode
Non-locational data might be found on which data sheets? a. defect diagram check sheet b. measles chart c. concentration chart d. recording check sheet
Non-locational data might be found on which data sheets? a. defect diagram check sheet b. measles chart c. concentration chart d. recording check sheet D= correct: A, B, C are types of check sheets that indicate location.
Non-value added activities on the factor floor are most clearly controlled by elimination of: A. Gemba B. Muda C. Poka-Yoka D. Kaizen
Non-value added activities on the factor floor are most clearly controlled by elimination of: A. Gemba B. Muda C. Poka-Yoka D. Kaizen B- correct; Gemba means factor floor; Kaizen means good change
Normal Probability Plots
Normal Probability Plots 1) Most of the points are near the center line, average 2) Some points are at the minimum and maximum points 3) When all the special causes of variation are eliminated, the process will produce a product that when sampled will produce a bell-shaped curve.
Np Chart/ Control Chart
Np Chart/ Control Chart 1) Assess attribute data to measure the number of times a condition exists in each sample, the condition may occur only once and the sample size is consistent. 2) Depicts a stable process 3) Measure Stage---used to guess the process baseline (variable control chart is more commonly used) 4) Improve Stage---used to find the number of errors in the process sample.---but the small error rate make Np chart ineffective
Number derived from sample data, which describes the data in some useful way is called?
Number derived from sample data, which describes the data in some useful way is called? Statistic
Objective of Statistical inference?
Objective of Statistical inference? To draw conclusions about population characteristics based on the information contained in sample
Of the key elements of an organizational plan, which of the following would be most likely to contain numbers and dates? A. Vision statement B. Tactical objectives C. Guiding principles D. Mission statement
Of the key elements of an organizational plan, which of the following would be most likely to contain numbers and dates? A. Vision statement B. Tactical objectives C. Guiding principles D. Mission statement B--correct because all goals should be quantifiable and measurable
On X-bar chart, many plot points are noted in zone B, some in zone C, and few in zone A, what could be occurring the process? a. Trends or over corrections b. Stratification c. Mixtures or systematic variation d. Improper calculation of the control limits
On X-bar chart, many plot points are noted in zone B, some in zone C, and few in zone A, what could be occurring the process? a. Trends or over corrections b. Stratification c. Mixtures or systematic variation d. Improper calculation of the control limits C= Correct
On an automotie secior, the APQP identifies what control plan for the early development states of the product?
On an automotie secior, the APQP identifies what control plan for the early development states of the product? Prototype Prelauch comes next , followed by the production phase.
On average, a company hires 4 people per month. In a given month, what is the probability that exactly 7 people will be hired?
On average, a company hires 4 people per month. In a given month, what is the probability that exactly 7 people will be hired? Answer= 0.0595 This is Poisson Distribution. P (X) = ( e ^-u) (mean) ^x _______________ X! x= 7 and m=4 gives the probability that 7 people will be hired, 0.0595. Can also get this answer from Poisson table. In this case, np= 4. The probability of 7 or less minus the probability of 6 or less (0.889) yields teh answer 0.06
One Sample t-test
One Sample t-test This test compares a sample to a known population mean, historical mean, or targeted mean. The population standard deviation is unknown and the data must satisfy normality assumptions. Given: n = sample size Degrees of freedom (dF) = n-1 Most statistical software will allow a variety of options to be examined from how large a sample must be to detect a certain size difference given a desired level of Power (= 1 - Beta Risk). You can also select various levels of Significance or Alpha Risk. For a given difference that you are interested in, the amount of samples required increases if you want to reduce Beta Risk (which seems logical). However, gathering more samples has a cost and that is the job of the GB/BB to balance getting the most info to get more Power and highest Confidence Level without too much cost or tying
One Tail test vs. Two-Tail Test
One Tail test vs. Two-Tail Test: 1) Any test of hypothesis has a risk associated with it and we generally are concerned with alpha risk (Type I error which rejects the null hypothesis when it is true). 2) Level of alpha risk determines the level of confidence (1-alpha) that we have in the conclusion. 3) Risk factor is used to determine the critical value of the best statistic which is compared to a calculated value.
One Tail test
One Tail test: 1) If the null hypothesis is established to test whether a sample value is smaller or larger than a population value, then the entire alpha risk si placed on ane end of a distribution curve . 2) Used for yes/no questions ---> determines if the true mean is within a critical region
One of Deming's 14 points of management states "Cease dependence upon inspection as a way to achieve quality" means: A. Many American companies employ too many inspectors B. Quality should be built into the product, not inpected in C. In most case, the worker should perform his own inspection and not rely on someone else. D. Most manual inpsection will miss 10%-20% of defects under typical working conditions.
One of Deming's 14 points of management states "Cease dependence upon inspection as a way to achieve quality" means: A. Many American companies employ too many inspectors B. Quality should be built into the product, not inpected in C. In most case, the worker should perform his own inspection and not rely on someone else. D. Most manual inpsection will miss 10%-20% of defects under typical working conditions. B-correct
One would expect to capture measured quantitative data with which of the following tools? a. pareto b. cWQC c. histogram d. P-chart
One would expect to capture measured quantitative data with which of the following tools? a. pareto b. cWQC c. histogram d. P-chart A= correct; CWQC= company wides quality control
One would suspect that process FMEA would result from: A. Studying the manufacturing and assembly process B. Interaction between the systems, subsystems and components C. Investigating the function requirements and design alternatives D. Review on failure modes before the first service
One would suspect that process FMEA would result from: A. Studying the manufacturing and assembly process B. Interaction between the systems, subsystems and components C. Investigating the function requirements and design alternatives D. Review on failure modes before the first service A- correct B= system FMEA; C = Design FMEA D= Service FMEA
One would that continuous flow manufacturing" a. Increases product damage b. Requires more storage and transport c. Reduces cycle times d. Solves most other production problems
One would that continuous flow manufacturing" a. Increases product damage b. Requires more storage and transport c. Reduces cycle times d. Solves most other production problems C-correct---Little law--Inventory= Flow time X Flow rate Seciton III 6/11
One-Tail Test
One-Tail Test 1) When testing the null hypothesis for whether a sample value is smaller or larger than a population value, then the entire alpha risk is placed on one end of the distribution
One-Way ANOVA
One-Way ANOVA In one-way ANOVA, the total variation has 2 parts: the variation among treatment means and the variation within treatments.
One-way ANOVA
One-way ANOVA The one-way analysis of variance (ANOVA) is used to determine whether there are any significant differences between the means of two or more independent (unrelated) groups
Optimum Quality Costs
Optimum Quality Costs 1) Most companies spend inadequate amount money on prevention activities ----> Low prevention costs but high failure costs or Failure costs are greater than appraisal costs. 2) Relationship between failure costs (internal & external) ----> consider changes in planning or product design. 3) Appraisal measure that are initially taken---> cause internal failures to increase and external failures to decrease
Which Measurement Scale? Central Location is Median
Ordinal Data Central Location is Median
Data arranged in some order but differences between values cannot be determined or are meaningless
Ordinal Data Data arranged in some order but differences between values cannot be determined or are meaningless
Organizational Performance and related strategic goals and objectives may be determined by 5 measures
Organizational Performance and related strategic goals and objectives may be determined by 5 measures: 1) Profit 2) Cycle time 3) Resources 4) Marketplace response 5) Short-term or Long-term emphasis
Origin of Quality Cost Measurements
Origin of Quality Cost Measurements---Reasons: 1) Products become more complex 2) Customers' expectations of product become more significant 3) Customers demanded service after the sale and expected failure remedy 4) Both supplier and customer costs expanded due to labor and mainence. 5) Management alternatices needed to be moneary terms.
Origins of Quality Cost Measurements
Origins of Quality Cost Measurements: Quality Cost Reporting was initiated in the past for the following reasons: 1) Increasingly complex products 2) More sophisticated customer expectations 3) Customers demanded service after sale and expected failure remedy. 4) Supplies and customer costs expanded due to labor & maintenance 5) Tech. specialists added to make improvements 6) Management alternatives needed in monetary terms.
Owners and Stakeholder & SIPOC
Owners and Stakeholder & SIPOC 1) Stakeholders ---stockholders, customers, suppliers, company management, employees, community, society 2) SIPOC only explains the supplier-process-customer relationship but this is only one of the many relationships in a business process. 3) Process owner oversight of the process while GB or BB are project managers working acrsos multiple processes ot identify stakeholders 4) Each stakeholder is both a supplier and customer, forming many closed loop processes that must be managed, controlled, balanced, and optimized for business to thrive. 5) Communication within the entire stakeholder community is channeled through internal company procesess ***Objective = improve individual process configurations to improve the overall outcome for all stakeholders.
P-chart
P-chart 1) Attribute Control Chart for FRACTION of non-conforming defects. 2) Process Yield=fraction of conforming units. 3) Based on Binomial Distribution---->p is the probability that any unit will not conform to the specifications. 4) Process is in control-----> if p-hat is within the control limits and absence of non-random patterns in the plotted points. 5) If one of more of the p-hats plot out of the control limits compared to the trial control limits, then must find assignable cause, revise the trial control limits, and discard the point out of the CL.
P-test
P-test 1) When testing a claim about a population proportion and we have a fixed number of independent trials with constant probabilities, and each trial has two outcome possiblities (bi-nomial experiment) 2) When np < 5 or n(1-p) <5, the binomial distribution is used to test hypotheses relating to proportion.
4 PERT Requirements
PERT Requirements: 1) All individual project tasks must be included in the network 2) Events & activities must be sequenced in the network to allow determination of the critical path 3) 3 estimates must be made for each activity in the network----optimistic, most likely, and pessimistic elapsed times. 4) Critical path & slack times for the proejct are calculated. ------> Critical path= sequence of task that needs the greatest expected time S= T(L) - T(E) ** Slack time= [Latest time event can occur / finished w/o project extension] - [Earliest date an event can occur]
PERT----Expected Time between Events 6 key points
PERT----Expected Time between Events: 1) Node = End/ Starting Pt for a group of activities = circle with event number inside----Two or more activities that merge at a common nodal point. 2) Time between events = arrow with number indicating time duration---Fig. >0 3) Expected Time between Events = = [(Optimistic time) + (4 *Most likely time) + (Pessimistic time) ] / 6 4) Burst Point = more than one task emanates from a common point. Fig 0 < 5) Projects not on the critical path may be delayed by an amount equal to the slack time without delaying the completion of the project 6) Task that end late may delay the project but also can modify the remaining tasks' critical path. 7) Critical Path- path with the longest time
Paired Comparison Hypothesis Test--- t-test
Paired Comparison Hypothesis Test--- t-test Used to test the difference between 2 sample means when the standard deviations of both samples are unknown
Paired T-test
Paired T-test The two-sample t-test is used to determine if two population means are equal. The data may either be paired or not paired. For paired t test, the data is dependent, i.e. there is a one-to-one correspondence between the values in the two samples. For example, same subject measured before & after a process change, or same subject measured at different times. For unpaired t test, the sample sizes for the two samples may or may not be equal.
Which Inference Test?
Paired T-test Two sample means Data taken in pairs Difference (d) is calculated for each pair
Paired t-test
Paired t-test A paired t-test is used to compare two population means where you have two samples in which observations in one sample can be paired with observations in the other sample. Examples of where this might occur are: • Before-and-after observations on the same subjects (e.g. students' diagnostic test results before and after a particular module or course). • A comparison of two different methods of measurement or two different treatments where the measurements/treatments are applied to the same subjects (e.g. blood pressure measurements using a stethoscope and a dynamap)
Pareto Diagram
Pareto Diagram 1) Creator = Vilfredo Pareto (Parisian economist who wrote about unequal distribution of wealth and contibuted to Fascism in Italy)----> Pareto only applied his principles to unequal income distribution 2) Juran applied the Pareto princeple as "universal"
SPC chart that graphically represents the frequency (not the importance) of attribute data arranged by category.
Pareto Diagram SPC chart that graphically represents the frequency (not the importance) of attribute data arranged by category.
Pattern and Trend Analysis
Pattern and Trend Analysis 1) Control charts or Trends can used to display changes in data patterns. 2) Data can be either summary (statis) or time sequence (dynamic) 3) Trend charts show patterns that indicate if a process is running normally or whether desirable or undesirable changes are occurring.
Percent Agreement Application
Percent Agreement 1) GR&R can be used for attribute data (yes/no, pass/fail) 2) Attribute agreement study ---> a) human variation in judgement or evaluation ("Within appraiser" variation) b) due to automatic measurement gauging where parts are automatically screened as good/ bad by machine
Percent Agreement
Percent Agreement 1) Percent agreement between measurement system and either reference value or variable being measured can be estimated using correlation coiefficient "r" 2) r= 0 then 0% agreement ; r= +/- 1, then 100% agreement
Define Percent Agreement
Percent Agreement: 1) Agreement between the measurement system and either reference value of the true value of measured variable 2) If X-varation is known, Y= variable---> Correlation coiffiecnt indication of % change in the dependent variable due to change in independent variable (Y) 3) r= 0---> 0% agreement between the measurement system and either reference value of the true value of measured variable 4) r= +/- 1 ---> 100% agreement
Percent GR&R to Tolerance
Percent GR&R to Tolerance 1) For product control situation where the measurement result and decision criteria determine "conformance or nonconformance" (that is 100% inspection or sampling), samples (or standard but be selected, but need not cover the entire process range) 2) Assessment of the measurement system is based on tolerance.
Percent GR&R to Variation
Percent GR&R to Variation For process control situation where the measurement result and decision criteria determine "process stability, direction, and compliance with the natural process variation" (that is SPC, process monitoring, capability, ad process improvement), the availability of samples over the entire operating range becomes important. Independent estimate of process variation (process capability study) is recommended when assessing the adequacy of the measurement stem for process control (that is % GR&R to variation)
Define Performance Benchmarking
Performance Benchmarking 1) Enables managers to assess their competitive positions through product and service comparisons 2) Focuses on elements of price, technical quality, ancillary product or service features, speed, reliability, and other performance characteristics.
Pilot run of 100 units, indicated the Cpk upper value of 1.8 and lower value 0.9. Customer requires Cpk minimum value of 1.25. What action should be taken?
Pilot run of 100 units, indicated the Cpk upper value of 1.8 and lower value 0.9. Customer requires Cpk minimum value of 1.25. What action should be taken? Center the process.
Plus and minus 3 standard deviations includes 99.73% of all points of a normal distribution. How many standard deviations would include 99% of all points of a normal distribution?
Plus and minus 3 standard deviations includes 99.73% of all points of a normal distribution. How many standard deviations would include 99% of all points of a normal distribution? Area under the curve of 99% implies that 1% is not under the curve---> 1% split into two tails is 0.5% Z-value that corresponds to 0.5% is 2.575
Point Estimate vs. Interval Estimate
Point Estimate vs. Interval Estimate An estimate of a population parameter may be expressed in two ways: Point estimate. A point estimate of a population parameter is a single value of a statistic. For example, the sample mean x is a point estimate of the population mean μ. Similarly, the sample proportion p is a point estimate of the population proportion P. Interval estimate. An interval estimate is defined by two numbers, between which a population parameter is said to lie. For example, a < x < b is an interval estimate of the population mean μ. It indicates that the population mean is greater than a but less than b.
Point Estimation
Point Estimation 1) If the mean and variance is known, the sample mean and sample variance are point estimaters 2) Point estimator should be unbiased----> expected value of the point estimator should be teh parameter being estimated 3) Point estimator should have minimum variance (the variacne should be smaller than any other point estimator of that parameter)
Point Estimation
Point Estimation A point estimate of a population parameter is a single value of a statistic. For example, the sample mean x is a point estimate of the population mean μ. Similarly, the sample proportion p is a point estimate of the population proportion P. Interval estimate.
Point estimate
Point estimate: If a single estimate value is desired (ie sample average), then a point estimate is determined by the X-gar
Poisson Distribution
Poisson Distribution 1) Model for the number of defects in one unit of product. 2) Both mean and variance equal the λ 3) Has skewed distribution-----> As the parameter λ larger, the Poisson distribution becomes more symeteric ***Binomial distribution with the parameters (n) that approaches infinity and (p) approaches zero would lead to Poisson Distribution if (n*p) = λ
Poisson Distribution
Poisson Distribution Basic assumptions: 1) Discrete distribution 2) Length of the observation period (or area) is fixed in advance 3) Events occurs at a constant average rate 4) Occurrences are independent Rare event
Poisson Distribution Application
Poisson Distribution Application 1) Number of events in an interval of time (or area) when the events are occurring at a constant rate 2) Number of items in a batch of random size 3) Design reliability tests where the failure rate is considered to be constant as a function of usage 4) Distribution of defect counts
Which Inference Test? Two sample means. Variances unknown, but considered equal
Pooled T-test Two sample means. Variances unknown, but considered equal
Term: All possible observations of similar items from which a sample is drawn
Population: All possible observations of similar items from which a sample is drawn
Positional variation can be broken into multiple components and placed into 3 categories
Positional variation can be broken into multiple components and placed into 3 categories: 1) Cyclinder = end-to-end, out-of-round each end 2) Batch = Top-to-bottom, side-to-side 3) Across width, front-to-back
Power of Test H0: u = u
Power of Test H0: u = u 1) The value of Beta risk is large if the mu is close to mu-zero to indicate that larger differences are easier to detect. 2) A shift in the mean away from the null increase the probability of detection. In general, as alpha increases, beta decreases and the power of (1- beta) increases. 3) A gain in power can be obtained by accepting a lower level of protection from alpha error 4) Increasing the sample size makes it possible to decrease both alpha and beta and increase power.
Power of a Test
Power of a Test
Process Capability Pp, Ppk In Relation to Z Scores
Pp, Ppk In Relation to Z Scores Ppk can be determined by diving the Z score by three. A z score is the same as a standard score; the number of standard deviations above the mean.
Practical Significance vs. Statistical Significance
Practical Significance vs. Statistical Significance 1) Levels of 5% or 1% are used to determine whether a hypothesis has statistical significance. 2) If p-value less than 5%---> statistically significant 3) Possible to have a hypothetical claim that is statistically significant but has no practical value.---generally when the sample size is inadequate.
Practical Significance vs. Statistical Significance
Practical Significance vs. Statistical Significance: 1) Hypothesis is tested to determine if a claim has significant statistical merit (5% or 1% used) 2) Statistical Significance = if the calculated test statistic has p-value below the critical level. 3) Practical significance= hypothesis or claim that is statistically significant but may not be worth the effort or expense to implement. (eg. 0.5 lb weight loss on a diet) ---> Generally occurs if sample size is not significant
Precision
Precision Same as Repeatability ---can repeat the same number by the same operator every time. ***To improve accuracy and precision, must have define test method and must be statistically stable.
Precision can be defined as
Precision can be defined as Agreement or closeness of the measurement of the same item
Precision/ Tolerance
Precision/ Tolerance 1) Ration between the estimated measurement error (precision) and the tolerance of the characteristic 2) Best to have a small P/T ratio to be small to reduce the effect of measurement error<-------or the net effect of all sources of measurement variability that cause an observed value to deviate from the master value.
Precision/ Tolerance (P/T)
Precision/ Tolerance (P/T) Ratio between the estimated measurement error (precision) and tolerance of the characteristic measured 1) Best for (P/T) to be small --> less measurement variability 2) Assume Measurement errors are independent, normally distributed, and independent of the magnitude of measurement when 6sigma is the standard dev
Precision/ Total Variation (P/TV)
Precision/ Total Variation (P/TV) 1) Best for (P/TV) to be minimized to reduce measurement variation on assessment of process variation.
Precision/ Total Variation
Precision/ Total Variation (P/TV) 1) Like P/T, it evaluates the acceptability of a measurement system 2) At P/T or P/TV increases, the ability to discriminate a change in process reduces. 3) When the measurement process is inadequate to detect part-to-part variation----> must use a smaller measurement variation
Prevention Cost Examples
Prevention Cost Examples 1) Capability Studies 2) Forecasting 3) Equipment Repair 4) Vendor surveys or evaluations 5) Quality Design 6) House Keeping 7) Time and Motion Studies 8) Pilot Projects 9) Controlled Storage
Cost of activities designed to precent poor quality in products/ services
Prevention costs: Cost of activities designed to precent poor quality in products/ services
Prioritization Matrices
Prioritization Matrices 1) Original Japanese matrix data-analysis tool that would arrange data into a matrix diagram allowing a large array of numbers to be seen at one time. 2) Degree of correlation would be entered into the cell 3) Very complex and not easy to use---> Heavy statistics calculations but computer optional
Probability Density Function
Probability Density Function (PDF) ***Describes the behavior of a random variable ---- For continuous variables, the pdf is the probability that a variate assumes the value x, expressed in terms of an integral between two points. 1) Smooth curve= represents population data 2) "Shape" of distribution----grouped frequency distribution. 3) Sampling errors / lack of randomness/ incorrect model = data points that above the "Smooth curve" outline of the bell-shaped curve. (aka. difference between the histogram bars/ sample data and the smooth curve/ population data) 4) Since probability density function represents the area under the curve, the area under the probability density function must equal one.
Probability of Steve passing Math is 0.7. Probability of passing History is 0.8. Probabily of passing both classes i 0.56. What of probability of passing either math or history?
Probability of Steve passing Math is 0.7. Probability of passing History is 0.8. Probabily of passing both classes i 0.56. What of probability of passing either math or history? 0.7 + 0.8 - (0.56)= 0.94
Probability that at least one defective in a random sample size of 10 drawn from a population that has been producing on the average. 10% defective units is?
Probability that at least one defective in a random sample size of 10 drawn from a population that has been producing on the average. 10% defective units is? Binomial probability calculation N= 10 r= 0 p= 0.1 P (r) =[ 10! / 0! (10-0 )! ] [ (0.1^0) (1- 0.1)^ 10-0] = 1 * 1 * (0.9 ^ 10) = Answer= 1 - (0.9^ 10)
Problems due to not Coding:
Problems due to not Coding: a) Inspectors trying to squeeze too many digits into small blocks on a check sheet form b) Reduced throughput and increased errors by clerks at keyboards reading and entering large sequences of digits for a single observation. c) Insensitivity of analytic results due to rounding of large sequence of digits.
Process Analysis & Documentation
Process Analysis & Documentation 1) Set of inter-related resources and activities which transform inputs into outputs with the objective of adding value 2) Tools used- flow charts, process maps, written procedures, and work instructions.
Define Process Benchmarking
Process Benchmarking 1) Focuses on discrete work processes and operating systems, such as the customer complaint process, billing process, or the strategic planning process. 2) Used to identify the most effective operating practices from many companies that perform similar work functions.
Process Capability--5 Applications
Process Capability Applications 1) Evaluation of new equipment 2) Reviewing tolerances based on the inherent variability 3) Assigning equipment to product 4) Routine process performance audits 5) Effects of adjustments during processing
Process Capability Index, Cpk
Process Capability Index, Cpk Description: Cpk is a short term process index that numerically describes the "within subgroup" or "potential" capability (Ppk is long term indicator) of a process assuming it was analyzed and stays in control.
Process Capability Indices
Process Capability Indices Discuss the various process capability indices that are commonly used as baseline measurements in the MEASURE phase and in the CONTROL phase. The concept of process capability pertains only to processes that are in statistical control. The capability indices of Ppk and Cpk use the mean and standard deviation to estimate probability. A target value from historical performance or the customer can be used to estimate the Cpm. Cp and Cpk are coined as "within subgroup", "short term", or "potential capability" measurements of process capability because they use a smoothing estimate for sigma. These indices should measure only inherent variation, that is common cause variation within the subgroup. Plotting subgroup to subgroup data as individuals (I-MR) will likely show an out of control chart and process that is likely in control just showing lot-lot variation, shift-shift variation or day to day variation which is expected. Therefore the SEQUENCE of gathering and measuring is mandatory to have a correct calculation of Cp and Cpk. The subgroups should be the same size and an the highest value is most likely obtained for Cp when the samples are collected with one operator on one shift on one machine with one set of tools, etc. Most common estimate for Cp and Cpk uses an average of the subgroup ranges, R-bar, in a process with only inherent variation (no special causes) formula that lowers the width of the data distribution (sigma) from the X-bar & R chart. This optimization of sigma reduces its spread and value further increasing the value Cp and Cpk over Pp and Ppk. Pp and Ppk use an estimate for sigma that takes into account all or total process variation including special causes (should they exist) and this estimate of sigma is the sample standard deviation, s, applies to most all situations. This estimation accounts for "within subgroup" and "between subgroup" variation. Cp, since it is a short term index and not dependent on centering and uses an optimal smoothed and reduced estimate for sigma, represents the process entitlement. Process entitlement the best a process can be expected to perform in terms of minimal variation under existing conditions. Cpk value can never exceed Cp. A perfectly centered distribution on the midpoint will have a Cpk = Cp. Any movement either way from the midpoint will have a "k" value of <1.0 and Cpk < Cp. In Cp and Pp, consider the numerator (USL-LSL) as a constant. As the estimate for standard deviation (sigma) of a distribution reduces and approaches zero the value of Cp and Pp will increase towards infinity. Cp and Pp are meaningless if only unilateral tolerances are provided, in other words if only the USL or LSL are provided. Both tolerances (bilateral) must be provided to calculate a meaningful Cp and Pp. A boundary can be used (such as 0 lower limit) but the meaning of Cp to Cpk will differ from the meaning using bilateral tolerances. The overall process performance indices, Pp and Ppk, most often uses the sample standard deviation, s, formula as an estimate for sigma. There are other methods available for estimating the overall (total) process sigma. The Cpk and Ppk will require two calculations, selecting the minimum is the value use as baseline and to compare to customer acceptability level. These can be calculated using unilateral or bilateral tolerances. Shown in the table below is the formula for bilateral tolerances where a LSL and USL are provided. If only one specification is provided (unilateral) then the value used for Cpk and Ppk is provided by the calculation that involves the specification limit provided. Pp and Ppk are rarely used compared to Cp and Cpk. They should only be used as relative comparisons to their counterparts. Capability indices, Cp and Cpk, should be compared to one another to assess the differences over a period of time. The goal is to have a high Cp, and get the process centered so the Cpk increases and approaches Cp. The same applies for Pp and Ppk. Cpk and Ppk account for centering of the process among the midpoint of the specifications. However, this performance index may not be optimal if the customer wants another point as the target other than the midpoint. The calculation of Cpm accounts for the addition of a target value.
Process Capability Indices There are two types of data being analyzed:
Process Capability Indices There are two types of data being analyzed: CONTINUOUS DATA: PPM DPMO Z-short term and Z-long term scores VARIABLE DATA: Cp Cpk Pp Ppk Cpm
Process Capability Study Objectives
Process Capability Study Objectives 1) Objective-----> to establish a state of control over the manufacturing process and then maintaining the state of control through time. 2) When natural process limits are compared with the specification range, the following options for course of action : a) Do Nothing------>if process limits are within the specification limits b) Change Specification Limits------> If they are too tight and need customer's approval for modification . c) Center the Process-----> if the process spread is the same as specification spread, then centering will bring the bulk of product within specifications. d) Reduce Variability -------> Partition the variation (within piece or batch-by-batch) and tackle largest offender first by using Experimental design to find the source. e) Accept Losses------> Accept the high loss rate and focus on efficient handling of scrap and rework
Process Capability estimates are strongest (but not always required) when:
Process Capability estimates are strongest (but not always required) when: 1) Process is in stable and in statistical control - use SPC charts to verify 2) Data is normally distributed (however data does not have to be normally distributed to use control charts) If not normal, the data is transformable Satisfies the Central Limit Theorem and normality assumptions apply
Process Decision Program Charts
Process Decision Program Charts 1) Used to chart the course of events that will take us from start point to final complex goal. ---> possible uncetainity of achieving intermediate events which could derail us from project completion . 2) Process Decision Program Chart (PDPC) is a technique designed to help prepare contingency plans. The emphasis of the PDPC is to identify the consequential impact of failure on activity plans, and create appropriate contingency plans to limit risks. Process diagrams and planning tree diagrams are extended by a couple of levels when the PDPC is applied to the bottom level tasks on those diagrams. .
Process Elements
Process Elements 1) Business Process Management ----> Methods that have evolved from the basic tenets of quality and continuous improvement to address business objectives and results 2) BPM is focused on understanding, controlling, and improving business processes to create value of all stakeholders.
Process FMEA is generally performed A. Just after design FMEA B. Just before the production tool is authorized C. Just after the design drawings are finalized D. As soon as the manufacturing defect is uncovered
Process FMEA is generally performed A. Just after design FMEA B. Just before the production tool is authorized C. Just after the design drawings are finalized D. As soon as the manufacturing defect is uncovered B-correct. Process FMEA is initiated before or after the feasibility stage, prior to production tooling, and accounts for all manufacturing operations. A and C are partially correct, in that PFMEA is started after the DFMEA but it could be some time befor production acitivies start up. PFMEA should be before manufacturing commences.
Process Mapping
Process Mapping 1) Key advantage = provides visual presentation of the process being described with the use of symbols rather than the clutter of words 2) Used to outline new procedures and review old procedures for viability and throughness. 3) Multiple Flowchart styles ----> person-to-person, action-to-action, and conceptual
Process Mean close to USL
Process Mean close to USL If your Process Mean (central tendency) is closer to the USL, use: Ppk = [ USL - x(bar) ] / 3 s, where x(bar) is the Process Mean. Process Mean close to LSL If your Process Mean (central tendency) is closer to the LSL, use: Ppk = [x(bar) - LSL ] / 3 s, where x(bar) is the Process Mean. Interpreting Ppk Scores A Ppk of 1 means that there is "half of a bell curve" between the center of the process and the nearest specification limit. That means your process is completely centered.
Who are process owners?
Process Owners: Those with responsibility for execution and implementation of a specific process.; Handle systems, subprocesses, and individual steps within processes. Function =Definition, execution, maintenance, and improvement of the process (aka. subject matter experts)
Process capability analysis is defined as: a. ability to make the process reliable and maintainable b. inherent variability of items produced by the process c. Variability allowed by the specification limits d. The determination that the process can meet the product specifications as intended
Process capability analysis is defined as: a. ability to make the process reliable and maintainable b. inherent variability of items produced by the process c. Variability allowed by the specification limits d. The determination that the process can meet the product specifications as intended D= correct
Process capability index calculated for stable, non-automated process. then, operatior is told to check samples at random and making centering adjustments to the process. Results?
Process capability index calculated for stable, non-automated process. then, operatior is told to check samples at random and making centering adjustments to the process. Results? Process Capability got worse.
Process capability indices (PCI)
Process capability indices (PCI) 1) Cp= ratio of tolerance to six sigma, or the upper specification limit (USL) minus the lower specification limit (LSL) divided by six sigma = [USL-LSL]/ 6sigma 2) Cpk = lesson the USL minus the mean divided by three sigma (mean) minus the LSL divided by three sigma. ---> the greater Cpk, the better 3) Capability ratio (Cr) = ratio of 1 divided by Cp.---> Lower the value of Cr, the better, with 1 being the maximum.
Why is process capability called a comparison between 2 independent worlds?
Process capability is the comparison between the world of specifications and the world of process spread Cp = (USL -LSL) / 6sigma = Specifications / Process Spread
What is a process element?
Process element = sequence of steps that uses inputs and produces a product or service as an output. Every process has input and outputs. Inputs= 8M 9money, material, machine/methods, management, measurement system, or mother nature Output= Services + Product (hardware, software, systems, data, information)
Process input, Outputs, and Feedback
Process input, Outputs, and Feedback 1) Must measure a process before it is improved 2) Process is measured by identifying process input variables, process outputs, and documenting their relationship via cause-and-effect diagram, relational matrices, flow charts and other tools 3) Measurement of Process Inputs (raw materials, human resources, or results from upstream process) can be used to optimize and control an upstream process. 4) Process input requirements should be stated so key measures of input quality can be controlled.---> Once the process capabilities are known, output measures can be used to determine if the process has remained in control. 5) Feedback from downstream process measurements can be used to improve an upstream process. 6) Planned experimentation ----isolating the effects of different, independent process variables----and Designing for Six Sigma ---eliminating potential sources of error-----are applied to complex inter-relationships found in the organizational feedback system
Process is centered and Cp is 0.8. This indicates that the specification range is what % of process width?
Process is centered and Cp is 0.8. This indicates that the specification range is what % of process width? 80%
Process is turning out end items that have no defects of type A, type B, or both. If the probability of type a defect is 0.1 and type B is 0.2, the probability that end item will have no defects: a. 0.7 b. 0.3 c. 0.72 d. .68
Process is turning out end items that have no defects of type A, type B, or both. If the probability of type a defect is 0.1 and type B is 0.2, the probability that end item will have no defects: a. 0.7 b. 0.3 c. 0.72 d. .68 C= correct P (AUB) = P(A) + A(B) - P(A*B) P(success) = 1- (Pfailure) type A= 0.1 Type b= 0.2 Both= (0.1 * 0.2) = 0.02 Probability of defects = 0.1 + 0.2 - (0.2) = 0.28
Process map is used to accomplish which of the following? a. display dynamic picture of process performance behavior b. focus attention on process problems in priority order c. diagram possible problem causes in a process d. track products, operator actions, or administrative procedures
Process map is used to accomplish which of the following? a. display dynamic picture of process performance behavior b. focus attention on process problems in priority order c. diagram possible problem causes in a process d. track products, operator actions, or administrative procedures D= correct Process map is a graphical depiction of a process.---Used to track products, operator actions, or administrative procedures (A)= control Chart (B) = Pareto chart (C) = Fish diagram
Process map know as SIPOC provides team members an understanding of the process from the view of: a. floor level b. very high level c. customer d. very detailed level
Process map know as SIPOC provides team members an understanding of the process from the view of: a. floor level b. very high level c. customer d. very detailed level B= correct; SIPOC has high level view of only 4-7 stpes.
Process mapping of activities and systems is most helpful in detecting: a. ways to eliminate written procedures b. deficiencies in the organizational structure c. Holes or gaps in the control system d. Improper use of statistical methods
Process mapping of activities and systems is most helpful in detecting: a. ways to eliminate written procedures b. deficiencies in the organizational structure c. Holes or gaps in the control system d. Improper use of statistical methods C= Correct Process mapping is good to visualize the process and find weaknesses. Organizational chart is a better source for determining organizational deficiencies. Flow chart does not identify improper statistical methods.
Process specification limits are unknown and the Standard deviation = 1.0, which of the capabilities can be determined? A. Cr B. Cp C. Pr D None of above
Process specification limits are unknown and the Standard deviation = 1.0, which of the capabilities can be determined? A. Cr B. Cp C. Pr D None of above D= correct
Product development process should consist: A. individual product developer B. Relay team of function-to-function specialists C. Internal Quality teams D. Multi-functional teams
Product development process should consist: A. individual product developer B. Relay team of function-to-function specialists C. Internal Quality teams D. Multi-functional teams D-correct
Production in large quantities has what advantage? A. Maximization of machine efficiencies B. Longer customer delivery lead times C. Additional product transportation expenses D. Potential product damage
Production in large quantities has what advantage? A. Maximization of machine efficiencies B. Longer customer delivery lead times C. Additional product transportation expenses D. Potential product damage A
What is Proficiency testing?
Proficiency Testing --- "Round Robin Testing" ------Measurement system or device is compared against the mean and St. deviation of other similar devices---->can find components of variation due to artifacts and instruments , especially if no national reference standards are present for specific range/ condition being measured.
Proficiency Testing / Round-robin Testing
Proficiency Testing / Round-robin Testing Measurement system compared against the mean or standard deviation of multiple other devices, all reporting measurements of the same or similar artifacts. 1) If two ore more artifacts are test by each device and the replicate reading taken ---> variation due to artifacts and instruments can be separated 2) Best used when no national standard reference available
Project Charter Role in Development of the Improvement Team
Project Charter in Development of the Improvement Team : 1) Acceptance & Development of project charter -----> critical element to forming an improvement team b/c it defines the following: a) Mission b) Scope of Operation c) Objectives d) Time Frame e) Consequences **** Purpose Statement of Charter explains why the team is being formed and identifies the objectives for Team
Project Closure
Project Closure 1) Final step on proving the project met established goals and objectives 2) Ensure that required documentation is completed and stored 3) Closure meeting with project sponsors to ensure that agreement and expectations were met.
Project Documentation
Project Documentation 1) Project proposal= includes objective, budget, & proposal plan 2) Status reports= communication vehicle to management or customer on the project progress.
Define Project Documentation
Project Documentation 1) Proposal usually in response to an improvement objective, project plan and budget. 2) Approval of proposal is management's indication of support for the project objectives and commitment to provide funding and resources. 3) During project implementation, status reports are the communication vehicle to management/ customer on the progress of the project
Project Monitoring Plan includes what?
Project Monitoring Plan 1) Purpose, frequency, and goal of monitoring 2) Reporting methods 3) Procedure for assistance requests 4) Reporting criteria for urgent/unusual events 5) Feed back loop responsibilities and assigned individual for feedback loop 6) Remediation action plan for poor outcomes.
Project Planning Tools
Project Planning Tools: Use to determine project timeline, required resources and estimating costs. 1) PERT 2) GANNT 3) CRITICAL PATH METHODS *** Work-breakdown structure identifies detailed activities for the plan and enables estimation of project costs.
Disciplined approach to monitoring how and when a project will be accomplished, with recognition of the system the the project is working in.
Project Planning: Disciplined approach to monitoring how and when a project will be accomplished, with recognition of the system the the project is working in.
Project Scope
Project Scope 1) Project boundaries that outline the team's activities, 2) Problems with market research/ prototype development/ Financial invenstments outside of scope
Project charter provides 8 advantages
Project charter provides 7 advantages 1) Less confusion 2) Defines subject boundaries 3) Identifies areas which should not be addressed 4) Identifies the deliverable product 5) Provides a basis for team goal setting 6) Authorizes team to collect relevant data 7) Provides access to needed resources 8) Approves time for team members to address problems
When is project risk analysis conducted?
Project risk analysis ---> performed early in the project's lifecycle--usually in planning stage and mitigation planning.
How is the project success/failure measured?
Project success/ Failure measured by: 1) Deadlines 2) Cost contrasts 3) Resource utilization 4) Goals/objectives.
Properties of Chi-Squre Distribution
Properties of Chi-Squre Distribution 1) Non-negative (It is action of two non-negative values) 2) Non-Symmetric 3) DF when working with single population variance is [n-1]
Properties of Student t- distribution
Properties of Student t- distribution 1) Bell-shapped but with smaller sample sizes showing increased variability (flatter) ---> less peaked than normal distribution with thicker tails 2) As sample size increases, the distribution approaches normal distribution. For n> 30, difference negligible 3) Unknown standard deviation 4) Unimodal, symmetrical population distribution 5) Variance greater than 1 but variance increases as sample size increases.
Provide 6 examples of Flow Chart Application
Provide 6 examples of Flow Chart Application 1) Purchasing--->processing purchase orders, placing actual purchases, vendor contract negotiations. 2) Manufacturing---> Processing returned goods, handling internal rejections, production processes, training new operators. 3) Sales----> Making sales call, taking order information, advertising sequences. 4) Administration---->Correspondence flow, processing times, correcting mistakes, handling mail, typing letters, hiring employees. 5) Maintenance---> p.m. scheduling and work order processing 6) Laboratory---> Delivery of samples, testing steps, selecting new equipment, mapping work flow
Purpose of Hypothesis Testing
Purpose of Hypothesis Testing: 1) To make statistical conclusion about accepting/ rejecting the hypothesis. 2) Comparison of a test statistic to a predetermined critical probability value known as alpha
Purpose of project scope
Purpose of project scope: 1) Ensure common understand the goal that project team will accomplish 2) Scope defined on the basis of the problem statement
Quality Cost Bases
Quality Cost Bases **Two or Three Cost base comparisons is normal. Quality costs are summarize as a report on monthly basis. 1) Labor Bases ------> Standard labor (planned) , Total direct labor worked 2) Manufacturing Cost Bases ----> Shop Cost Output (direct labor, materials, indirect costs) + Manufacturing Cost of Output (packing/shipping, provision for complaints, total shop cost output. production engineering expenses) 3) Sales bases--------->Net sales billed, Contributed Value (aka. Net Sales minus Direct Materil) 4) Unit bases------> quality costs, dollars per unit of production.
Quality Cost Improvement Sequence---9 steps
Quality Cost Improvement Sequence 1) Define Company's quality goals ----> Position among competitors + desired long-term reputation 2) Translate Quality goals in Quality Requirements ---> Specific tests, Control types, Outgoing Quality levels 3) Estimate the capability of process/ machines/ systmes 4) Create a program aligned with company goals 5) Determine resources requirements for project 6) Set up quality cost categories of prevention, appraisal, and failure 7) Get estimates of the 3 quality cost categories 8) Analyze the quality cost data for major improvement candidates 9) Pareto Principle to isolate specific areas for investigation.
6 Quality Cost Pitfalls
Quality Cost Pitfalls 1) Perfectionalism in numbers---> lengthy debates over precision of quality cost figures may result in delays in moving the initiative forward with lot of total savings 2) Other data pitfalls ----> Presentation to managers should stimulate discussion on improvement proposal and not data validity 3) Inclusion of non-quality costs ---> management must decide exclusion or inclusion of pure product quality waste 4) Implications of reducing quality cost to zero ----> Quality Cost presentation must regonize that zero defects can't be feasible. 5) Reducing Quality costs but increasing total company costs ------->May need to ensure that reduction in quality costs will not increase total costs. 6) Understatement of Quality Costs----->most commonly due to dealing only quality costs in excess of some normal standard. Prevention is to challenge the standard.
Quality Cost reports became vehicle for two reasons
Quality Cost reports became vehicle for two reasons: 1) Determine the status of cost control efforts 2) Identify opportunities for reducing costs by systematic improvements
Quality guru who believed the best approach to understanding the purpose of quality system would be the absolutes of Quality management? A. Feigenbaum B. Crosby C. Deming D. Juran
Quality guru who believed the best approach to understanding the purpose of quality system would be the absolutes of Quality management? A. Feigenbaum B. Crosby C. Deming D. Juran B-correct---> Croby's 4 absolutes of quality management
Question: Which of the following describes the 95% confidence interval of a 20% absentee rate in a department with 30 people? (A) 6% to 34% (B) 8% to 32% (C) 13% to 27% (D) 17% to 23%
Question: Which of the following describes the 95% confidence interval of a 20% absentee rate in a department with 30 people? (A) 6% to 34% (B) 8% to 32% (C) 13% to 27% (D) 17% to 23% Answer: A 6% to 34%. This is a confidence intervals for proportion question. p + or - Z (α/2) * SQRT( (p*(1-p))/n ) p = 0.2 α = 5% (Use this to look up the Z Score on the Z table.) n = 30 p + or - Z (α/2) * SQRT( (p*(1-p))/n ) 0.2 + or - Z (5%) * SQRT( (0.2*(1-0.2))/30 ) 0.2 + or -1.96 * SQRT( 0.0053) 0.2 + or - 0.1431 0.2 + 0.1431 = 0.3431 => 34.31% => Round down to 34% 0.2 - 0.1431 = 0.05686 => 5.68% => Round up to 5%
R-chart is most closely related to which of the following? a. C-chart b. S-chart c. u-chart d. X-bar chart
R-chart is most closely related to which of the following? a. C-chart b. S-chart c. u-chart d. X-bar chart B= correct R-chart is used to monitor process variance. Range, the difference between the largest and smallest measures in the sample, is used as an estimation of variance, except the standard deviation, S, is estimated directly , rather than using the range method. S-chart is used when the sample size is large, N>10, and when the sample size is variable. The rand method quaickly loses accuracy as the sample size increases, make the S-chart more desirable.
RPN is the measure of the risk of a failure mode. The ratings are on a 1-10 scale. If FMEA has 10 failure modes with RPN of 50 to 300, improvement team should focus on which of the following? A. Work on those failures with RPNs greater than 50 B. Use the Pareto principle to prioritize highest RPNs C. Identify failure modes with high severity rankings, followed by high RPN D. Use the Pareto principle and start with top 20% of the failure modes.
RPN is the measure of the risk of a failure mode. The ratings are on a 1-10 scale. If FMEA has 10 failure modes with RPN of 50 to 300, improvement team should focus on which of the following? A. Work on those failures with RPNs greater than 50 B. Use the Pareto principle to prioritize highest RPNs C. Identify failure modes with high severity rankings, followed by high RPN D. Use the Pareto principle and start with top 20% of the failure modes. C- correct --III-pg 30
Random Sampling
Random Sampling Definition---every unit in the population has the same chance of being selected. 1) Best for time or economic constraints. 2) Requires samples to be representative of the lot and not just the product 3) Sampling without randomness make the plan ineffective. ----Sampling sequence must be random as well
Range Method
Range Method 1) Reproducibility is the variability introduced into the measurement system by bias difference of different operators 2) Rang method ---simple way to quantify the combined repeatability and reproducibility of a system (can't do it separately---need Average and range method to separate it)
Which Measurement Scale? Central Location is Geometric Mean
Ratio Central Location is Geometric Mean
An extension of interval feel that includes an inherent zero starting point. Both differences and ratios are meaningful
Ratio Data An extension of interval feel that includes an inherent zero starting point. Both differences and ratios are meaningful
Define Rational Subgroups
Rational Subgroups Subgroups or samples should be selected so that if assignable causes are present, then: Chance of differences BETWEEN subgroups should be maximized Chance of differences WITHIN subgroups should be MINIMIZED
Recording Check Sheets
Recording Check Sheets 1) Used to collect measured or counted data 2) Data is collected by making tick marks -- ( tally sheet) 3) Caution--leave enough room for individual measurements to be written. 4) Measured data = physically measured information ---eg. pH, airpressure, or amount of downtime in hours.
Refer to the Venn Diagram in the answer side: If the probability of event A is 20%, the probability of event B is 30%, and the probability of event A intersecting event B is 8%, what is the probability of neither event?
Refer to the Venn Diagram in the answer side: If the probability of event A is 20%, the probability of event B is 30%, and the probability of event A intersecting event B is 8%, what is the probability of neither event? Answer= 58 % (A ∪ B) = P (A) + P (B) - P ( A ∩ B) (A ∪ B) = 0.2 + 0.3 - 0.08 = 42% Probability of neither event= 100% -42% = 58%
Referring from the equation below, if U and V are independent chi-square random variables with m and n degrees of freedom, then A: A= [ U/m] / [V / n]
Referring from the equation below, if U and V are independent chi-square random variables with m and n degrees of freedom, then A: A= [ U/m] / [V / n] If U and Va are independent chic-square random variables, the A follow F-distribution A= F distribution
Regression Analysis
Regression Analysis 1) Identifies when independent variables are influenced by one or more dependent variables 2)Measure Stage----> Evaluates the degree to which a measurement system is linear 3) Analyze Stage---->Used to explore connections between metrics and process factors. 4) Improve Stage----> Used to connections after improvement have been made
Relational Matrix is a problem-solving tool which helps to: a. Show cause-effect relationship between input and output variables b. focus attention on problems in priority order c. generate a large number of improvement ideas d. determine where non-conforming parts exist
Relational Matrix is a problem-solving tool which helps to: a. Show cause-effect relationship between input and output variables b. focus attention on problems in priority order c. generate a large number of improvement ideas d. determine where non-conforming parts exist A= correct. B= pareto diagram c= brainstorming d= inspection
Relationship between Exponential Distribution and Poisson Distribution
Relationship between Exponential Distribution and Poisson Distribution ** The number of occurrences of some event has a Poisson Distribution with a parameter λ, then the distribution of the interval between occurrences is exponential with parameter λ
Relationship between process capability target and product specifications?
Relationship between process capability target and product specifications? Process capability target is usally tighter than product specifications
Variation in measuring equipment when measured by one appraiser in the same setting at the same time
Repeatability Variation in measuring equipment when measured by one appraiser in the same setting at the same time ---Expressed as standard deviation
Repeatability & Gage R&R
Repeatability & Gage R&R ** R= repeatability 1) Individual R averages= differences between appraisers 2) If R (a) < (R (b) = appraiser R (a) did a better at getting the same repeated measurement of the same part than B; appraiser B had wider variation
Repeatability and Reproducibility
Repeatability and Reproducibility 1) Assuming gate accuracy and sensitivity is assured--------->
Repeatability of R & R study is most similar to?
Repeatability of R & R study is most similar to? Accuracy of measurements
Repeatability of an R & R study can be determined by examining the ?
Repeatability of an R & R study can be determined by examining the ? Variation between individual inspector and within their measurement readings
Reproducibility
Reproducibility 1) Reproducibility of a singe gage is checked by comparin resuls of different operators taken at different times --->will affect both accuaracy and precision of reported Values
Variation in measurement when measured by two or more appraiser multiple times
Reproducibility Variation in measurement when measured by two or more appraiser multiple times
Reproducibility & Gage R&R
Reproducibility & Gage R&R * X-bar= Reproducibility 1) If X-bar (a) and X-bar (b) are very close but X-bar (c) is quite different ---> Appraiser C's equipment measurement has some bias.
Reproducibility in an R & R study would be considered the variability introduced into the measurement system by:
Reproducibility in an R & R study would be considered the variability introduced into the measurement system by: Bias difference of different operator (change in instrument differences over the operating range, which actually defines linearity) Total measurement system variation include BOTH reproducibility and repeatability
When a single gage is checked by comparing the results of different operators taken at different times.....Term?
Reproducibility.
Requirements for characteristics to be measured in process capability study
Requirements for characteristics to be measured in process capability study: 1) Characteristics should indicate a key factor in quality or product/process 2) Possible to adjust the value of characteristics 3) Operation condition the affect the characteristic should be defined and controlled.
Risk Analysis and Management
Risk Analysis and Management 1) Risk Analysis conducted to inform stakeholder about the project risks and contingencies that develop in mitigating the risks. 2) Risk= Probability of an event or cost of not reaching the goal 3) Must understand the potential consequence of occurrences or non-occurences of project failure can be due to cost, performance, or schedule risks
Risk Assessment Matrix Definition
Risk Assessment Matrix Definition 1) Risk probability is based on the likelihood that the risk will occur during project execution 2) Each risk ranked individually on scale of 1-3 for severity and probability ---> RPN= (Severity) (probability) Higher RPN, More urgent attention
Risk Management Phases & Definitions ---Risk Planning
Risk Management Phases & Definitions ---Risk Definition-----> Development and Documentation of a systematic methodology for identifying, analyzing, and tracking risk issues. Includes development of contigency plans, assessments, and resource allocation plan. Inputs: " FT RRRN"----> Focust Points, Techniques, Responsibilities, Resources, Requirements, Needs
Risk Management Phases & Definitions ---Risk Assessment
Risk Management Phases & Definitions ---Risk Assessment Definition-----> Identify/ Analyze Project Risks to increase the ability of meeting cost, performance, and schedule requirements Inputs: "R- SALE" ---Review of plans, Similar systems, Assessments, Lessons learned, Expert Interviews
Risk Management Phases & Definitions ---Risk Handling
Risk Management Phases & Definitions ---Risk Handling Definition-----> Identify, evaluate , select, and implement actions to fix risk at the lowest possible level given project constraints and goals Inputs: " AM CAT" ---Avoidance, Mitigation, Control, Acceptance, Transference.
Risk Management Phases & Definitions ---Risk Monitoring
Risk Management Phases & Definitions ---Risk Monitoring Definition-----> Continuous Evaluation & Tracking system to ensure that implemented actions to mitigate risk are working as planned. Inputs: "DD PRS" ---Danger List, Decision Analysis, Performance tracking, Reaction Models & Simulations.
Risk Management--7 Continuous Process steps
Risk Management-- 7 Continuous Process steps" 1) Identify : Search/ Locate risk before they become a problem 2) Analyze ---Transform risk data into decision-making information 3) Plan---Translate risk information into decision actions 4) Track-- monitor risk indicators and action throughout the project 5) Mitigate--Reduce the impact 6) Communicate--Provide visibility & feedback data, internal and external to project on current or emerging risk Communication = Key element to a successful Risk Aversion Program.
Risk Mitigation and Verification
Risk Mitigation and Verification 1) Conducted throughout project lifecycle 2) Begins with identifying activities the team can perform to reduce the likelihood that the risk will occur and .or reduce its impact 3) Regularly review this plan to check for new risks Risk verification = ensures that risk mitigation reasonably prevent the reoccurrence of risk.
Risk of using SIPOC
Risk of using SIPOC 1) Making the diagram too detailed may details the focus of the sigma projects 2) Best to limit to 4-7 process blocks to keep clarity
Role of Feedback in measuring process
Role of Feedback in measuring process 1) Feedback from downstream process measurements can be used to improve upstream process 2) Interrelationships between organizational feedback system is the target for planned experimentation for designing for six sigma 3) Designing for six sigma= the use of planned experimentation of isolate several process variables to eliminates potential sources of error.
Role of Project Plan
Role of Project Plan 1) Key stakeholders and team members involved 2) Project Scope 3) Resources needed 4) Deliverables 5) Project Constraints (potential things that can cause undesirable performance or nonconformance)
Rolled Throughput Yield
Rolled Throughput Yield 1) Cumulative calculation of yield or defect through multiple process steps 2) RTY helps team to focus on the major problem source. 3) Significant difference in individual yields can suggest improvement opportunities.----> Eg. If the Yeild of Welding= 90% ---> Fab (yeild= 86%) ---> Assembly (Yield= 65%) ***The large drop in yield for the Assembly step means that must do an improvement project for Assembly step.
Rolled throughput yield (RTY)
Rolled throughput yield (RTY) 1) Applies to yield from a series of processes 2) RTY= multiplying individual process yields Throughput yield = e ^-DPU Example: 4 process yield: 0.994, 0.987, 0.951, 0.99 RTY=( 0.994) (0.987) (0.951) (0.99) = 0.924
Run Charts ---> Purpose & Application
Run Charts 1) Purpose = visual indicator of nonrandom patterns 2) Application = Real-time feedback required fro variables data. Shows how stable a process is behaving and to detect special causes
SIPOC Diagram
SIPOC Diagram Close of SIPOC model will show Six Sigma is based on the concept of closed-loop business system: 1) Any change in process output will be related to one or more changes in supplier, inputs, and processes (SIPS) 2) if all SIPS are stable, then output is stable 3) A change in "O" means that one or more SIPS must be changed (a) If the O's do change---> changes in SIP may be used to predict and control changes in O's (b) If the O's DO NOT change---> SIPs being changes are robust and may process process savings opportunities. 4) Apparent violations of this rule indicate that the process model is incomplete (an SIP or O parameter is missing...a chance to build organization wisdom) *** Closed-Loop relationships between SIPs and O's provide a methods to define process correlations and possible cause-effect relationships.
SIPOC can help everyone "See" the business from overall process perspective in 4 ways
SIPOC can help everyone "See" the business from overall process perspective in 4 ways: 1) Displaying cross-functional activities in simple diagrams 2) Providing a framework applicable to process of all sizes. 3) Helping maintain the big picture business perspective 4) Providing methods for adding additional detail as needed ** Must consider the levels of business process.
SIPOC process map provides a view of the process that contains how many steps?
SIPOC process map provides a view of the process that contains how many steps? 4-7 steps
Sales Cost Bases
Sales Cost Bases 1) Net sales billed 2) Contributed value (net sale minus direct material)
Sample Size & type I and II Errors
Sample Size & type I and II Errors: Increasing sample size with reduce both alpha and beta risks.
Sample Size and Sampling Frequency
Sample Size and Sampling Frequency 1) Larger sample size make it easier to detect small shifts in the process. 2) If process shift is relatively large, then we use smaller sample sizes that those that would be employed if the small shift. Frequency of Sampling (Allocating Sampling Effort) 1) When detecting shifts, best to take large samples very frequent 2) High-volume manufacturing processes or the presence of many types of special cause variation prefer smaller, more frequent samples
Sample of means approaches normal distribution when: a. original distribution in normal b. Random sample variance approaches the population variance c. Sample size increases d. mean control chart demonstrates control
Sample of means approaches normal distribution when: a. original distribution in normal b. Random sample variance approaches the population variance c. Sample size increases d. mean control chart demonstrates control C= Correct
Sample of n observation has mean X-bar and standard deviation S(x) >0. If a single observation, which equals the value of the sample mean X-bar, is removed from teh sample, what is true. a. X-bar and S(x) both change b. X-bar and S(x) both stay same c. X-bar stays same and S(x) increases d. X-bar stays same and S(x) decreases
Sample of n observation has mean X-bar and standard deviation S(x) >0. If a single observation, which equals the value of the sample mean X-bar, is removed from teh sample, what is true. a. X-bar and S(x) both change b. X-bar and S(x) both stay same c. X-bar stays same and S(x) increases d. X-bar stays same and S(x) decreases Answer C---X-bar will not change when an observation equal to the average is removed. Sx must increase slightly according to the following formula: Sx= Square root of [sum of (X- mean) ^2] / Sample size minus 1) Number will not be affected in the above equation bu the denominator will become smaller (n-2) which causes S (x) to get larger
Scatter Diagram --Purpose & Application
Scatter Diagram -- 1) Purpose = Detects possible correlation or association between two variables (cause and effect)
Scatter Diagrams
Scatter Diagrams 1) Correlation originates from the following: a) Cause-effect Pattern b) Relationship between one cause and another cause 2) Not all scatter diagrams have linear relationship 3) Regression line ---" Best Fit Line"---> must analyze the scatter diagram before making a decision in correlation statistics.
Scatter diagram used to plot the number of defects produced in a day verses the number of coffee the supervisor had that day. What can be concluded a. Supervisor should drink more coffee b. Supervisor will drink tea c. Nothin
Scatter diagram used to plot the number of defects produced in a day verses the number of coffee the supervisor had that day. What can be concluded a. Supervisor should drink more coffee b. Supervisor will drink tea c. Nothing One risk with scatter diagrams is that a relationship between two variables may appear to exist when in fact no relationship exists. Unless there is another information as to why the coffee consumptions has an influences on defects, we should not make any conclusions Section VI-- 31
Define Schedule performance index
Schedule performance index Measures of project's efficiency to schedule as expressed in the ratio of earned value to planned value.
Percent of work accomplished on time
Scheduled performance index = Percent of work accomplished on time
Sensitivity
Sensitivity 1) A gage should be sensitive enough to detect difference in measurement as slight as 1/10 of the total tolerance specification or process spread, whichever is smaller. 2) Inadequate discrimination will affect both accuaracy and precision of reported Values
Sequential Sampling
Sequential Sampling 1) Similar to multiple sampling plan except Sequential sampling can continue indefinitely 2) Sampling usually ended after the number inspected has exceeded 3 times the sample size 3) Used for costly or destructive testing with sample sizes of one and are based on the probability ratio test
Sequential sampling plans and ASN
Sequential sampling plans and ASN Sequential sampling plan have low ASN (average sample number) and samples are taken one item at a time. However, these plan are more complex and difficult to administer
Setting goals with either Short-term or Long-term Results.
Setting goals with either Short-term or Long-term Results: 1) Emphasis on Quarterly stock dividends have led American managers to have short-term outlook . 2) Japanese and Europeans prefer to have smaller, short term profit to ensure the company's long-term growth 3) Reduced Product cycle time for both new 4) Profit Margin needed to operate a business should be optimized for all stakeholder requirements---> Maximum profits are not taken due to internal stakeholder interests------->Must turn down the option for reinvestment, new equipment purchases, wage/salary increases to maintain an optimal level of dividends or investments for stockholders 5)
Shop Cost of Output
Shop Cost of Output 1) Direct labor 2) Direct material 3) Indirect Costs
Short Term Capability
Short Term Capability 1) Control limts based on short-term processes 2) Less variation with smaller data quantities 3) When sample size is too small---> Control charts with false, out-of-control patterns
Short-term tactical plans are defined by: A. Defined by Customer B. Set before objectives can be determined C. Supportive of strategic objectives D. Normally opposite of long range objectives.
Short-term tactical plans are defined by: A. Defined by Customer B. Set before objectives can be determined C. Supportive of strategic objectives D. Normally opposite of long range objectives. C is correct! ---Short-term tactical plans or operational plans are used in implement long and short-term strategic plans. Functional departments, develop short-term objectives, budgets, policies, and programs to support the organizations' strategic plans. Short-term plans may be developed to satisfy customer needs, but are not defined by the custoerm. Therefore, A= incorrect. B= wrong--->objectives must be defined before the plans to meet those objectives can be determined. D= false---both short and long-term quality plans should support strategic objectives
Short-term vs. Long-term Capability
Short-term vs. Long-term Capability 1) Process Average and Spread----> dependent on number of units measured or duration that process is measured. 2) Small Variation ----> if process with one operator on one shift with one equipment 3) Increased variation as more factor are included----time, multiple operators, lot materials, environmental changes, ect. Smaller the data amount, lesser the variation. 4) Control limits for short-term process evaluation are closer together than control limits for long-term process and produce false, out-of-control patterns. 5) Shorter Runs ---> use 3-10 peces without adjustment and modified X-bar and R chart-----> Calculated value is compared with critical value and then Control limits are established using inflated D4 and A2 values 6) Attribute Data vs. Variable Data---->variable data gives more information about the process----aka a resonable estimate of the process mean and variation using 25-30 groups of 5 samples each ****Better to use Variable Data for estimating Process Capability. 7) Attribute Data----> requires 25 groups of 50 samples each
Sigma levels
Sigma levels
Significance test using ordinal data
Sign or Run Test: Significance test using ordinal data
Simple Regression
Simple Regression Used to describe straight line that best fits a series of ordered pairs (x,y). ---> Finding the "best- fitting" line is an effort to minimize the deviation of the point away the best line
Simplificiton of paperwork, minimazation of WIP, and reduction of finished goods inventories, can be achieved utilizing .....?
Simplificiton of paperwork, minimazation of WIP, and reduction of finished goods inventories, can be achieved utilizing .....? Kanban pull system
Since many variables are important in control charting, what is the risk of having an operator plot a large number of characteristics?
Since many variables are important in control charting, what is the risk of having an operator plot a large number of characteristics? Distraction from the actual process itself. It's unlikely that CTQ characteristic will be overlooked. Control charting a small number of key items might be value-added work.
Six Sigma & Process Owner
Six Sigma & Process Owner 1) Six Sigma defines process owner as senior manager in charge of process. 2) Goal= improve individual process configurations to improve the overall outcome for all stakeholders. 3) Stakeholder = both supplier and customers, forming closed loop processes that must be managed, controlled, balanced, and optimized.
4 Six Sigma Metrics & Mike Harry
Six Sigma Metrics & Mike Harry Mikel Harry and Richard Schroeder, two pioneers of Six Sigma: ----> "An organization's profitability is determined by what it chooses to measure and how it measures it." 1) They point out that most companies need to change what they measure. Many companies use customer satisfaction to measure success. They believe that the metrics of customer satisfaction can lead to the identification of Six Sigma projects, and that the results of those projects should increase customer satisfaction.
Six Sigma project benefits should include which of the following? A. Reduced profits B. Improved process capability C. Increased Defects D. Delayed warranty claims
Six Sigma project benefits should include which of the following? A. Reduced profits B. Improved process capability C. Increased Defects D. Delayed warranty claims B---correct
Six sigma belt has a 2 ^ (5-2) fractional factorial design. Only 2 of the 5 factors remained important after the factorial analysis. Escalation of this DOE to an optimization model will be best accomplished by: a. performing a new full factorial of the 2 factors b. performing a response surface experiment c. decreasing the degrees of freedom of the original DOE d. adding an additional factor level.
Six sigma belt has a 2 ^ (5-2) fractional factorial design. Only 2 of the 5 factors remained important after the factorial analysis. Escalation of this DOE to an optimization model will be best accomplished by: a. performing a new full factorial of the 2 factors b. performing a response surface experiment c. decreasing the degrees of freedom of the original DOE d. adding an additional factor level. B= c0rrect. In the 1st part of the experiment, the screening objective has clearly been accomplished. Out of the 5 factors, 3 have not proved to significant for the chosen response. Remaining 2 are now the focus of attention for further experimentation
Six sigma mean 3.4 ppm considering a shift in the mean of 1.5 standard deviations. What is the value of 6 sigma without the 1.5 standard deviations shift in the mean.
Six sigma mean 3.4 ppm considering a shift in the mean of 1.5 standard deviations. What is the value of 6 sigma without the 1.5 standard deviations shift in the mean. answer= 0.002 ppm A shift in the mean of 1.5 standard deviation s is an assumption that considers any processes natural tendency to loose capability over time. Using a normal disbribution tale, six sigma , without the 1.5 process shift, is 0.002
Smoothing of work load in all steps is called" a. level loading b. minimal cycle time c. point of use processing d. perfection.
Smoothing of work load in all steps is called" a. level loading b. minimal cycle time c. point of use processing d. perfection. A=correct
Some 10 production units are known to contain 3 defective units. If 2 units are inspected, what is the probability that both will be good?
Some 10 production units are known to contain 3 defective units. If 2 units are inspected, what is the probability that both will be good? N= 10 r= 3 defective units P= 0.3 of being defective P= 0.7 of being good P (A ∩ B ) = P (A) * P (BIA) P (A ∩ B) = ( 7/10) (6/9) = 42/ 90 = 0.467
Sources of Variation
Sources of Variation (Fig. 14.8, pg. 197) 1) Overall Variability ---> Either part-to-part variability or measurement system variability 2) Measurement System variability ---> either due to Variation in gauge (repeatability) or variation due to operator (reproducibility) 3) Reproducibility ---> Either due to Operator or Operator by part
Special Roles---Gatekeeper & Boundary Spanners
Special Roles 1) Gatekeepers= individuals who are at the crossroads of communications channels and are center of information because of their jobs. 2) Boundary Spanners= individuals who have positions that link them with others outside of the work units and exist to exchange information between groups
Drift in absolute value over time
Stability Drift in absolute value over time
Define Stable Process
Stable Process 1) Absence of special cause variation after 20-30 subgroups plotted
Stable system has been control charted fro some time. Sample size historically been units of 4 with average range of 6. Once can conclude that the process spread can be determined to approximately what value?
Stable system has been control charted fro some time. Sample size historically been units of 4 with average range of 6. Once can conclude that the process spread can be determined to approximately what value? S= Average Range (R-bar) / d^2 = 6 / 2.059 = 2.914 The six S spread = 17.48 XI-12
Stages of Project Management
Stages of Project Management 1) Planning 2) Scheduling 3) Controlling--ensuring that desired results are reached
Stakeholder Analysis
Stakeholder Analysis: 1) As part of the Define phase, attempts to remove/reduce resistance to chance must be made by identifying the stakeholders and planing to involve them in the change process, removal of pitfalls, or alternate solutions. 2) Need a communication plan to keep stakeholders involved----> Should document the perceived scale of commitment or resistance of stakeholders
Who are stakeholders?
Stakeholders Those with vested interest in the process and/or its products and outputs. Generally, stakeholders of an organizations include customers, employees, investors, and communities.
See the curve for Standard normal distribution.---VII- 18
Standard normal distribution is a special case of normal distribution with mean of 0 and standard deviation of 1. Normal distribution is transformed into standard normal disbution using the formula--- Z= (X- mean) / Sigma
Stem and Leaf Plot
Stem and Leaf Plot 1) Best for plotting variable & categorical data 2) Stems= data grouped by class intervals 3) Leaves= smaller interval data
Stem and Leaf Plot
Stem and Leaf Plot 1) Each number is divided into 2 parts: Stem (one of more of the leading digits) & Leaf (remaining digits) ---> Example : 76 ---> 7 (stem) 6 (leaf) 2) To find the medan---> organize the stems by magnitude and find the middle number
Stem and Leaf Plots
Stem and Leaf Plots-- John Tukey 1) Manual method for plotting both categorical and variable data sets. 2) Data are grouped by class intervals as "Stem" ------smaller data increments = " Leaves" 3) Allows for data to be read directly from the diagram whereas histogram may lose individual values as frequencies within the class interval.
Stem-and-leaf plot ---> Purpose & Application
Stem-and-leaf plot 1) Provides numerical data information about the contents of the cells in frequency distribution. 2) Application = quickly identify any repetitive data within the class interval.
Steps for process capability studies
Steps for process capability studies 1) Measurement system verification---- remove sources of variation via process capability assessment to prep for process stability monitoring 2) Id. rational subgrouping of 5 samples---> 5 consecutive samples taken at equal intervals from a process and average/ range plotted to observe stability whee the subgroup size is one. 3) Normality required for continuous data
Steps in conducting Gage R&R
Steps in conducting Gage R&R (pg 190 ASQ ) 1) Inform appraisers of measurement criteria & inspection method (Ensure training) 2) Handpick study samples cover spread (avoid random sampling) 3) Study location not visible to appraisers but experimenter present during R&R study 4) Multiple appraisers perform measurements one-by-one. 5) Randomized data collection sheet entered into the calculation tabular sheet.
Steps in determining whether Normal distribution for process capability study
Steps in determining whether Normal distribution for process capability study 1) Histogram using original data (not the average) from control chart 2) If symmetrical tails and data points mostly around median---> Normal distribution 3) If not normal ---> Can transform non normal data to normal data using Box-Cox transformation or Johnson transformation
Steps involved in Statistical inference
Steps involved in Statistical inference 1) Define problem and choose between one-tail and two-tail hypothesis. 2) Select test distribution and critical value of the test statistic reflecting the degree of uncertainty that can be tolerated. 3) Calculate test statistic value and make inference by comparing calculated value with critical value.
Stockholders & Profits
Stockholders & Profits 1) Profit margin optimized for stakeholder requirements 2) Programs/ Project require ROI 3) When stockholder returns maximized, then wages, salary increases, re-investment, new equipment purchases should be reduced. 4) Maintain stockholder dividends, investments, and personnel costs.
How are Storyboards used?
Storyboards: 1) Convey project information involving changes that are easier to draw or photograph after pictures for proposed projects 2) Best for project re-design 3) Storyboards formatted as DMAIC
Strategic Benchmarking
Strategic Benchmarking 1) Examines how companies compete and is rarely industry-focused. 2) It moves across industries to find winning strategies
Strategic goals must be subdivided. Thus , they are: A. Delegated B. Distributed C. Accountable D. Deployed
Strategic goals must be subdivided. Thus , they are: A. Delegated---> Assigned goals B. Distributed C. Accountable D. Deployed---> goals are spread out into attainable portions. D-correct
Strategic plan implementation at the function level requires: A. Functional level metrics B. Company quality policy with everyone understanding it C. Functional short and long-term strategic goals D. Customer Focus
Strategic plan implementation at the function level requires: A. Functional level metrics B. Company quality policy with everyone understanding it C. Functional short and long-term strategic goals D. Customer Focus C= correct ( section II- 37/41)
Strategic quality goals are subdivided into: A. Major benchmarks B. Loss Functions C. Number tactical quality goals D. Appropriate Metrics
Strategic quality goals are subdivided into: A. Major benchmarks B. Loss Functions C. Number tactical quality goals D. Appropriate Metrics C= Correct (Section II-37) Strategic quality goals must be moved down to the lower levels of the organization via some technique. The rest are not deployment techniques
Stratified Sampling
Stratified Sampling Basic assumption of sampling----> sample is selected from a homogenous lot ----> Hetergenous lot---eg. car parts in a pile but made by different machines, different condition, or different lines 1) Stratified Sampling-----> Selection of random samples from each group/ process that are different from other similar groups or processes 2) Results in a mix of samples that can be biased if the proportion of samples does not reflect the relative frequency of the groups. -----> Importance? a) User must be made aware of possibility of stratified groups b) Data reports must state that the observations are relevant only to the sample drawn and may not necessarily reflect the overall system.
Student T-test
Student T-test 1) Applies to samples drawn from a normally distributed population. 2) Used fro making inferences about a population mean when the population variance is unknown and the sample size is small. 3) t-distribution is never wrong for any sample size----> Sample size 30 is the crossover point between the t and Z test. 4) Works well for bell-shaped distribution.
Student t- distribution
Student t- distribution continuous probability distributions that arises when estimating the mean of a normally distributed population in situations where the sample size is small and population standard deviation is unknown. 1) Combination of standard normal random variable and chi-square random variable 2) Z= standard normal random variable ; X(2) is chi-square rand variable
Student t- distribution application
Student t- distribution application 1) Hypothesis testing = statistical significance of the difference between two sample means 2) Confidence intervals around the means 3) Linear regression analysis **Replaces normal distribution when standard deviation unknown. *****Compensates for error in estimated standard deviation.
Student t-test is applicable when a. collecting attribute data b. limited measured data c. sample sizes of 100 or greater d. comparing population variances
Student t-test is applicable when a. collecting attribute data b. limited measured data c. sample sizes of 100 or greater d. comparing population variances B- correct; (D) = F-distribution t- distribution deals with small samples of measured data. For measured data with large sampe sizes, the standard normal Z-table is ussed.
Student t-test
Student's t-test, method of testing hypotheses about the mean of a small sample drawn from a normally distributed population when the population standard deviation is unknown.
Suppose that 5 bad electron tubes are mixed with 8 good tubes. If 2 tubes are drawn simultaneously, what is the probability that both are good?
Suppose that 5 bad electron tubes are mixed with 8 good tubes. If 2 tubes are drawn simultaneously, what is the probability that both are good? Answer= 14/ 39 Multiplicative Law of Probability: P ( A ∩ B) = P (A) * P (B) Although both samples are drawn simultaneously, the two events are dependent and analyzed as if the tubes were drawn sequentially. P ( A ∩ B) = ( 8/ 13) * (7/ 12) = 56/ 156 = 14/ 39
System Variation
System Variation 1) 85% of all process problems due to common cause variation . 2) Fundamental changes in the process are done to remove common cause varation ----> like changing equipment, machinery, methods, materials, or other factors. 3) Management exhorts the worker to "do the right thing the first time" but are really tampering with the system and causing unpredictable results. 4) Nelson Funnel--------> Adjustment or Tampering? --- >shows how a stable system is inappropriately adjusted; show what happens if people react to individual unit in a stable process a) Statistical stability of a process indicates that if left unaltered, the process will continue to produce outcomes that show a stable pattern of variation. b) Nelson's funnel experiment examines four strategies for adjustment. They are Rule 1: No adjustment is made. The process is left to run. Rule 2: Every time a marble lands away from the target, the funnel is moved from its current position an equal distance from the target, but in the opposite direction. Rule 3: The funnel is moved back to being centered over the target and is then moved from the target in the opposite direction as the marble missed the target and an equal distance. Rule 4: Try to repeat the last performance by moving the funnel over the landing point of the last drop.
The recognition/ identification and consideration of all various individual elements that interrelate with a common purpose toward a whole function of a unit
Systems Thinking: The recognition/ identification and consideration of all various individual elements that interrelate with a common purpose toward a whole function of a unit The use of tools and methods available to understand what is being done at a specific operation and how that activity affects tasks and products further downstream and how prior tasks and product affect the process being reviewed. Goal is to reduce variation and satisfy customers *** Thinking that we can have both continuous improvement and control charts in control is not systems thinking.
TPM in relation to lean enterprise system means what?
TPM in relation to lean enterprise system means what? Total productive maintenance---- to maximize equipment effectiveness.
Takt time takes on a great importance in: a. Fishbone diagrams b. 5S housekeeping organization c. Poke-Yoke d. Continuous flow manufacturing
Takt time takes on a great importance in: a. Fishbone diagrams b. 5S housekeeping organization c. Poke-Yoke d. Continuous flow manufacturing D= correct
Purpose and Application of Tally
Tally: 1) Purpose = quick count of the total quantity and by class interval. Provides visual ideas of distribution shape. 2) Application= Used to count defect quantity by type/class/category
Key points on Team Formation
Team Formation 1) 5-9 members (7 ideal) ---> based on project scope and size 2) Experts (resource) + Stakeholder (part of the team 3) Teams <5 --> less interaction problems; Teams > 9 --> greater diversity 4) Outsiders make raise questions to stimulate ideas but should be moderated to prevent team frustration.
Team Leadership Style & Forming
Team Leadership & Forming---> Directing Style 1) Close supervision 2) Listens to feedback 3) Encourage and welcomes team 4) Instructs on what to do when/where/how 5) Identifies opportunities for skills development to meet team goals.
Team Leadership & Norming
Team Leadership & Norming---> Supporting Style 1) less directive, more supportive 2) Encourage team decision-making 3) Helps transition to performing to prevent regression to earlier stages 4) Emphasis on ground rule, scope, and responsibilities
Team Leadership & Performing
Team Leadership & Performing ---> Delegating 1) Reduced directive & supportive behaviors in daily operations 2) Monitoring of goals and performance 3) Watchful for dynamic changes or major changes.
Technique used to discover the most probable important factors in an experimental trial is called ?
Technique used to discover the most probable important factors in an experimental trial is called ? Screening Experiment This type of design tends to separate important from unimportant factors.
Term "metric" refers to: A. Unit of measurement B. Metric system c. Science or weights and meaurements D. Evaluation method
Term "metric" refers to: A. Unit of measurement B. Metric system c. Science or weights and meaurements D. Evaluation method C-correct
Test Statistic
Test Statistic 1) Calculated value that is compared with the critical value (p-value) when testing the null hypothesis.
Test for validity of normality assumption?
Test for validity of normality assumption? Chi-square test
F-Distribution & Student T-test
The F-distribution shares one important property with the Student's t-distribution: Probabilities are determined by a concept known as degrees of freedom. Unlike the Student's t-distribution, the F-distribution is characterized by two different types of degrees of freedom — numerator and denominator degrees of freedom. The F-distribution has two important properties: 1) It's defined only for positive values. 2) It's not symmetrical about its mean; instead, it's positively skewed.
The Poisson distribution can be used to approximate the binomial distribution under which of the following conditions?
The Poisson distribution can be used to approximate the binomial distribution under which of the following conditions? When p is equal or small than 0.1 and the sample size is large..
The advantage of using the modern DOE, rather than the classical, is that: .....?
The advantage of using the modern DOE, rather than the classical, is that: .....? Fewer terms and measurements are needed for valid and useful information. The key to this question is the word classical., which means varying one factor at a time while holding all other factors constant. This approach causes havoc for complex problems. Fixed factors do vary, which can waste time and money. The traditional approach can produce invalid or in conclusive results. Modern DOE (including fractional factorial, improved 3 factor designs and Latin Square logic) squeeze a large amount of valid information into a few trials
The average number of flows in a large plate glass is 0.25 per pane. Standard deviation of the Poisson distribution is: ??
The average number of flows in a large plate glass is 0.25 per pane. Standard deviation of the Poisson distribution is: ?? Answer= 0.5 _ C = Poisson average _ Poisson sigma= square root of C = square root of 0.25= 0.5
The care you drive to work has a 90% chance of starting in the morning . It is blocked by your spouse's car which has an 80% chance of starting. Both cars are blocked by your son's car which has 70% chance of starting. What is the probability of getting to work in your car?
The care you drive to work has a 90% chance of starting in the morning . It is blocked by your spouse's car which has an 80% chance of starting. Both cars are blocked by your son's car which has 70% chance of starting. What is the probability of getting to work in your car? Answer= 0.504 P ( A ∩ B ∩ C ) = P (A) * P (B) * P (C) 0.504 = 0.9 * 0.8* 0.7
The control chart that is most sensitive to variations in measurement is: a. p-chart b. np chart c. c-chart d. X-bar and R-chart
The control chart that is most sensitive to variations in measurement is: a. p-chart b. np chart c. c-chart d. X-bar and R-chart D= correct Most Sensitive ATTRIBUTE Chart----> p-chart Most Senstive Control Chart----> X-bar and R-chart
The distribution of a characteristic is negatively skewed. The sampling distribution of the mean for large samples, taken from the same distribution is_____?
The distribution of a characteristic is negatively skewed. The sampling distribution of the mean for large samples, taken from the same distribution is_____? Approximately Normal = Answer Question requires a review of the answers in light of the central limit theorem. The central limit theorem states that the sample means will be more normally distributed around the mean than individual readings (X's). As n increases, the X means approach a normal distribution with mean "mu"
The distribution that has a mean equal to the variance is the: ???
The distribution that has a mean equal to the variance is the: ??? Answer= Poission _ Poisson Average= mu = (N * P) = C _ Poisson Variance = σ2= u = (n * p-bar) = C
The equation for joint probability , of 2 accident events under any circumstance is given by " P (A I B) = P (AIB) X (P(B) If fault A does not enhance occurrence of fault B in any way, the probability of accident, when P(A) = 0.1, P(B) = 0.05 is given by?
The equation for joint probability , of 2 accident events under any circumstance is given by " P (A I B) = P (AIB) X (P(B) If fault A does not enhance occurrence of fault B in any way, the probability of accident, when P(A) = 0.1, P(B) = 0.05 is given by? Example of multiplicative law of probability where event A and event B are independent. P (A ∩ B ) = (PA) (PB) = 0.1 * 0.05= 0.005
The most common subgrouping scheme for X-bar -R-control charts to separate the variation: a. within stream verse stream-to-stream b. within time verses time - to - time c. within piece verse piece-to-piece d. inherent process verses error of measurement
The most common subgrouping scheme for X-bar -R-control charts to separate the variation: a. within stream verse stream-to-stream b. within time verses time - to - time c. within piece verse piece-to-piece d. inherent process verses error of measurement B= correct. Multitude of techniques such as stratified studies, error of measurement and multi-vari charts are used segment all of the answer choices.
The most effective and efficient method of solving quality problems for a product is to concentrate efforts in the area: A. Design B. Production c. Quality improvement D. Lean techniques.
The most effective and efficient method of solving quality problems for a product is to concentrate efforts in the area: A. Design B. Production c. Quality improvement D. Lean techniques. A- correct---It has been stated that 80% of the qulity problems are desing related. Given this fact, the best option is prevent
The normality of residuals for factor A indicate a uniform behavior around zero, what can be concluded from this fact? a. There is something wrong with the model. Go back to the planning stage b. Normality of the residuals has been demonstrated by the uniform behavior. c. Factor A is a nuisance factor, as been demonstrated by the uniform behavior. d. Factor A is statistically significant because of the uniformity of residuals.
The normality of residuals for factor A indicate a uniform behavior around zero, what can be concluded from this fact? a. There is something wrong with the model. Go back to the planning stage b. Normality of the residuals has been demonstrated by the uniform behavior. c. Factor A is a nuisance factor, as been demonstrated by the uniform behavior. d. Factor A is statistically significant because of the uniformity of residuals. B= correct. Residuals are estimates of experimental error obtained by subtracting the observed response from the predicted response. Residuals behaving according ot the normal distribution is one of the assumptions behind DOE. Often experiments don't check these assumptions and get confusing results that could be otherwise explained by first checking the assumptions of measurement system capability, process stability, and normality of residuals.
The results of lean principles/ thinking transformation show the greatest reduction in the areas of : A. Throughput times and inventories B. Customer errors and in -house scrap C. Safety injuries and capital investment D. Productivity and injury areas
The results of lean principles/ thinking transformation show the greatest reduction in the areas of : A. Throughput times and inventories B. Customer errors and in -house scrap C. Safety injuries and capital investment D. Productivity and injury areas A- correct; there in increase in productivity; 90% reduction in Throughput times and inventories. 50% reduction in customer errors, in-house scrap, injuries, and product development times .
The term severity in FMEA describes: A. Difficulty completing the FMEA form B. Possible impact to a system user of failure C. Likilihood of failure D. Time for which the system is expected to be down
The term severity in FMEA describes: A. Difficulty completing the FMEA form B. Possible impact to a system user of failure C. Likilihood of failure D. Time for which the system is expected to be down C- Correct
The tool/ techniques most widely used by a number of automotive suppliers to control material flow is called ??
The tool/ techniques most widely used by a number of automotive suppliers to control material flow is called ?? Kanban
The visual factor would be supported to the greatest extent by: a. Muda and gemba b. Kanban and 5S c. Gemba and Kanban d. 5S and muda
The visual factor would be supported to the greatest extent by: a. Muda and gemba b. Kanban and 5S c. Gemba and Kanban d. 5S and muda B= correct Parts of 5S (color coding, outlines, and markings) support the visual factory.
Theory of Constraints concentrates mainly on" A. Understanding customer needs B. Developing value stream map C. Achieving on-time goals D. Removing process bottlenecks
Theory of Constraints concentrates mainly on" A. Understanding customer needs B. Developing value stream map C. Achieving on-time goals D. Removing process bottlenecks D-correct
There are large number of potential human errors. What are the possible countermeasures for inexperience?
There are large number of potential human errors. What are the possible countermeasures for inexperience? 1) visual aid 2) work instruction s 3) work standardization 4) skill building
There are several types of control plans. Identify the appropriate control plan to be used for part mock-ups. a. prototype b. pre-launch c. production d. generic
There are several types of control plans. Identify the appropriate control plan to be used for part mock-ups. a. prototype b. pre-launch c. production d. generic A= correct (B) is used for near -production processes. (C) is usde for mass production of a part
Three Type of Prioritization Matrices
Three Type of Prioritization Matrices 1) Full Analytical Criteria Method -----> Most complex of 3 methods; Requires a set of matrices to form a final matrix. ---> Decision based on numerical values can generally be obtained as a result 2) Consensus Criteria methods--- This process is made to use by combining a tree and matrix diagramming methods to carry out a pair-wise assessment of items resulting to narrowing down to a most preferred or most effectual priority wise sequence of events. 3) Combination ID/ Matrix Method.---> Used to prioritize options but does not numerically value of cause-and-effect relations. In L-shaped matrix, which compares all of the options to each other, the strength values can be developed.
Three Types of Checksheets
Three Types of Checksheets 1) Location or concentration diagram:----> When you rent a car, you probably receive a document with the sketch of the car which allows you to circle any damages, dents or scratches on the car with a corresponding mark on the diagram. 2) Graphical or Distribution check sheet: --------->Using the graphical form, the person collecting the data is able to visualize the distribution of the data. For example, the number of people in line at the registration desk at 15 minute intervals could be counted to determine the staffing needs and the size of the waiting room. 3) Tabular check sheet or tally sheet-------> : The tally sheet is commonly used to collect data on quality problems and to determine the frequency of events. For example, the tally sheet is useful for understanding the reasons patients are arriving late for appointments, causes for delays in getting the lab results back, etc. It is also useful in determining frequency of occurrence, such as number of people in the line for blood tests at 6:00 am, 6:15 am, etc., to understand staffing needs.
Three levels of product costs
Three levels of product costs 1) prevention costs 2) Appraisal costs 3) failure costs
Three types of Decision Distribution:
Three types of Decision Distribution: 1) t-distribution 2) F-distribution 3) Chi-square distribution
Three types of Flow Charts
Three types of Flow Charts: 1) Person-to-person 2) Action -to-action 3) Conceptual
Three types of checklists
Three types of checklists? 1) Measles chart--locational data 2) checklists---counted data 3) Recording checklist---measured data
Three ways that calculations for process capability are different from process capability calculations
Three ways that calculations for process capability are different from process capability calculations *** Both are exactly the same in calculation process except for : 1) Historical data from control charts should be excluded but okay to include other forms of variation 2) If multiple machines are producing the same part, then the capability of each machine should be determined independently 3) Machine capability should come from consecutive part measurements from the same machine at or near the same time (perhaps 20 to 40 parts).
To state that a model in an experimental design is fixed indicates that???
To state that a model in an experimental design is fixed indicates that??? The levels used for each factor are the only ones of interest. So a balanced design is then considered at only those levels. Based upon analysis, factors may then be adjusted to other fixed levels for subsequent experimentation. The objective is to achieve optimum performance.
Tool boards, jidohka devices, and red-lights all combine to: a. make problems visible b. prevent defective products c. maintain management control d. display targets for improvement
Tool boards, jidohka devices, and red-lights all combine to: a. make problems visible b. prevent defective products c. maintain management control d. display targets for improvement A= correct. Tool boards, jidohka devices, and red-lights= examples of visual factory techniques
2 Tool used to identify the process boundaries?
Tool used to identify the process boundaries? 1)SIPOC: = best for capturing requirements of process and customer. 2) Basic process model= give a high-level look at process and may be too simplistic to plan out process boundaries or identify problems.
Tools for documenting process inputs and outputs ?
Tools for documenting process inputs and outputs ? 1) Cause-and-effect diagrams 2) Relational matrices 3) Flow charts
What tools used to express business performance measures ?
Tools used to express business performance measures: 1) Balanced scorecard 2) Performance to established goals
Traditional Business process
Traditional Business process 1) Vertical Silos---built around functional boundaries 2) Production starts with the process inputs and flow across many vertical functions and horizontal business levels to produce process outputs (products, goods, and services) 3) Differences in function, organizational structure, vocabulary & location are sources of confusiton and defects. 4) Business process can fail if the functional relationships not clearly understood.
Traditional Cost Concept
Traditional Cost Concept 1) Financial reports used to find the Variance ( difference b/w actual costs with budgeted costs) 2) Departmental budgets= costs needed to carry out department functions.
Traditional Cost Concepts
Traditional Cost Concepts 1) Financial Reports used to compare actual costs with budgeted costs. 2)
Tree Diagram/ Systematic Diagram--4 key uses
Tree Diagram / Systematic Diagram 1) Systematic method to outline all of the details needed to complete a given objective. ---> same cause in an affinity or fishbone diagram can be filled into tree diagram and can be done after brainstorming session. 2) Similar to value analysis 3) Used for : a) To develop element for a new product b) Show the relationship of a production process c) Create new ideas in problem solving d) Outline the stops to implement a project.
Two Approaches to Constructing Rational Subgroups
Two Approaches to Constructing Rational Subgroups (Control Charts) Approach 1:--------> Units produced simultaneously are used to detect process shifts-----"Snapshot" of the process at each point in time where sample collected----(Reduces WITHIN sample variability & Maximizes BETWEEN samples variation) Approach 2: -------> Random sampling used when control chart employed to make decisions about the acceptance of all production units over a sampling interval ------If process mean drifts between sampling intervals, may stretch out the process control limits and create a false shift in process variability.
Two Sample t-test
Two Sample t-test This test is used when comparing the means of: 1) Two random independent samples are drawn, n1 and n2 2) Each population exhibit normal distribution 3) Equal standard deviations assumed for each population The degrees of freedom (dF) = n1 + n2 - 2
Two constant values are often used to calculate P/T AND P/TV ratios. What is the origin of the values 6 and 5.15 in the ratio calculations ?
Two constant values are often used to calculate P/T AND P/TV ratios. What is the origin of the values 6 and 5.15 in the ratio calculations ? They represent 99.73% and 99% of total population of measurements, assuming normality. Assuming normality, 6 represents 3 standard deviations or 99.73% and 5.15 represents +/- 2.575
Two elements of statistical inference
Two elements of statistical inference 1) inference 2) measure of validity
Two key advantages of Process Mapping
Two key advantages of Process Mapping: 1) Depicts process using symbols, arrow, and words without the clutter of sentences 2) Can be used outline new procedures 3) Can be used to review old procedures for viability and thoroughness
Two key deliverables of Define Stage?
Two key deliverables of Define Stage? 1) Project Plan 2) Detailed knowledge of the current state of the problem
Two major estimators used to analyze sample values to arrive at population probabilitites
Two major estimators used to analyze sample values to arrive at population probabilitites: 1) Point estimation 2) Interval estimation
Two measures for evaluating the acceptability of the measurement system
Two measures for evaluating the acceptability of the measurement system 1) Precision/ Tolerance (P/T) 2) Precision/ Total Variation (P/TV)
Two micrometers are used to measure the same quality characteristic (thickness in this case). The mircometer at headquarters has ore decimal places than the one being used at the plant. The mircrometer at headquarters is more: a. accurate b. precise c. advanced d. sensitive
Two micrometers are used to measure the same quality characteristic (thickness in this case). The mircometer at headquarters has ore decimal places than the one being used at the plant. The mircrometer at headquarters is more: a. accurate b. precise c. advanced d. sensitive C= correct; Accuracy refers to the comparison with a standard making (a) wrong. Precision refers to the ability to repeat measurements making (b) wrong.
Two purposes of Define stage
Two purposes of Define stage 1) Define the project management process 2) Define the problem or issue that will be targeted.
Three types of Discrete Distribution
Two types of Discrete Distribution 1) Binomial distribution 2) Poison distribution 3) Hypergeometric distribution
Two types of Failure Costs
Two types of Failure Costs: 1) Internal failure costs= costs that occur BEFORE to delivery/shipment/customer/ service 2) External failure = costs that occur AFTER to delivery/shipment/customer/ service
Two- Tail Test
Two- Tail Test Hypothesis test that determines whether a population shift has occurred in either direction---> allowable alpha error is then divided into two equal parts.
Two-Tail Test
Two-Tail Test: 1) If a null hypothesis to test whether a population shift has occurred in either direction than two-tail test is required 2) Used to determine if a difference exists --> determine if the true mean is within the upper or lower alpha critical regions.
Two-way ANOVA
Two-Way ANOVA Tests to determine whether there are significan difference between the means of two or more independent (unrelated) groups aims at assessing the main effect of each independent variable but also if there is any interaction between them.
Two-Way ANOVA
Two-Way ANOVA Two Way ANOVA is used to analyze the effect of two random factors on a Critical-To-Characteristic (see concept Factors and Levels). A factor is said to be random when levels are randomly chosen from a population of possible levels and we wish to draw conclusions about the entire population of levels, not just those used in the study. For example, Two Way ANOVA type of analysis is generally used in Gage R&R studies.
Type I Error
Type I Error 1) Error that occurs when the null hypothesis is rejected when it is , in fact, true 2) Alpha= producer's risk =probability of making type I error
Type I error
Type I error Concluding the process is out of control when it is really in control
Type II Error
Type II Error 1) Error that occurs when the null hypothesis is not rejected when it should be rejected 2) Beta- consumer risk = probability of type II error
Type II error
Type II error Concluding that the process is IN control when it is really out of control.
Types I Error
Types I Error 1) Alpha error---> when a true hypothesis is rejected. 2) Also known as "Producer's Risk"
Types II Error
Types II Error 1) Beta error----> when a false hypothesis is not rejected. 2) "Consumer's Risk" -----> eg. adverse process change 3) Small alpha risk increases the Beta risk
Types of Process Inputs
Types of Process Inputs: 1) Needs (2) Ideas (3) Exceptions (4) Requirements 5) Information 6) Data (7) Documents (8) Resources
Types of Check sheet
Types of check sheets: Commonly used check sheets are 1) tabular check sheets or tally sheets, 2) location check sheets and 3) graphical or distribution check sheets.
Types of process outputs
Types of process outputs 1) Designs 2) Decisions 3) Measurements 4) Products/ Services 5)Authorizations 7) Actions 8) Solutions 9) Proposals
U-Chart
U-Chart 1) Attribute Control Chart for NUMBER of non-conforming defects PER UNIT----can be % or ratio
Ultimate Goal of SIPOC
Ultimate Goal of SIPOC 1) Ultimate goal is to identify essential work flows and sources of variation in the work over time 2) Can be adapted to a number of essential support processes. 3) Process mapping, flow charting, and affinity diagrams can be used to identify the major blacoks or steps in a process of system.
Unit Cost Bases
Unit Cost Bases: 1) Quality costs, dollars per unit of production 2) Quality cost related to production
Upon completion of FMEA. what critical even should be established next? A. Ensure that process owner is in charge of FMEA B. Designate engineer to follow-up on recommended actions C. Review documents at regularly scheduled intervals D. Have Cross-functional team assigned to each FMEA to review activities
Upon completion of FMEA. what critical even should be established next? A. Ensure that process owner is in charge of FMEA B. Designate engineer to follow-up on recommended actions C. Review documents at regularly scheduled intervals D. Have Cross-functional team assigned to each FMEA to review activities A- correct--project ownership is turned over to the project owner after the consultants are done
Upward Flow of Communications
Upward Flow of Communications 1) Information relayed from the bottom/grassroots to higher levels 2) If management acts on the information from below, then lower levels gets motivated or empowered. 3) To encourage upward communication, managers should keep an open-door policy, surveys, questionaires, suggestion systems, shift meetings, breakfast meetings, ect.
Use of Analytical statistics to estimation of process baseline
Use of Analytical statistics to estimation of process baseline 1) Analytical statics ---used to distinguish special and common cause variation in dynamic, moving processes. 2) Statistical process control---operational defintion of special cause variation---notes the location and level of variation.
Use the data below Raw data= 307, 309, 310, 315, 310 Coded data = 7,9,10,15,9, 10 What is the X-bar?
Use the data below Raw data= 307, 309, 310, 315, 310 Coded data = 7,9,10,15,9, 10 What is the X-bar? Average of the raw data is 10. Average of coded data is 10. True X-bar should be expressed in the same terms as the raw data. Considered the coded data average to be X-bar- C (where C is consant) Answer= 310 Section VI-17
Using Six sigma, a company with 4.5 sigma will have a failure rate of: A. 3.4 ppm B. 233 ppm C. 1350 ppm D. 6210 ppm
Using Six sigma, a company with 4.5 sigma will have a failure rate of: A. 3.4 ppm B. 233 ppm C. 1350 ppm D. 6210 ppm C-correct; D= 4 sigma levelsl B- 5 sigma level
Using the PDCA process to design a customer survey, while implementing a customer feedback and improvement process is an example of: A. Critical path method B. Customer driven company C. PDCA process within a PDCA process D. Reactive verses a proactive approach
Using the PDCA process to design a customer survey, while implementing a customer feedback and improvement process is an example of: A. Critical path method B. Customer driven company C. PDCA process within a PDCA process D. Reactive verses a proactive approach C= correct ----> Section II--27/28
Variable Data/ Continuous
Variable Data Any real number----4.69, -1.4, --->measurable data that tell how long, what volume, or how much? 1) Measured data is more precise and more informative than counted Data but is expensive to collect.
Variable Width Box Plot
Variable Width Box Plot The other common variant that shows more information than the standard fixed width box plot is called the variable width box plot (like the plot at the top of this page). But this is only valuable if comparing more than one box plot since the width is irrelevant is just displaying one box plot. One common convention is to make the width of the boxes for group of data is proportional to the square roots of the number of observations in a given sample.
Variable control chart subgroup are generally 3,4,5, 6 for which of the following reasons? a. they permit an opportunity for process changes within the subgroups b. they fit onto traditional chart paper very well. c. they are small enough so that data averages will not follow the normal distribution d. they permit a separation of within time from time-to-time variation.
Variable control chart subgroup are generally 3,4,5, 6 for which of the following reasons? a. they permit an opportunity for process changes within the subgroups b. they fit onto traditional chart paper very well. c. they are small enough so that data averages will not follow the normal distribution d. they permit a separation of within time from time-to-time variation. D= correct. Control chart paper was developed to support a logical control chart sample size. Sample size should be chosen to fit a handy form. Large (not small) sample size permit an opportunity for process changes within the subgroup. Sample sizes of 3, 4, 5, 6 are large enough (not small enough) to permitt averages to follow the normal distribution.
Variable vs. Attribute Data
Variable vs. Attribute Data 1) Characteristics : a) Variable ---measurable, continuous, "counting data" b) Attribute --Discrete (Good/bad); Countable 2) Types of Data a) Variable --length, volume, time b) Attribute-- No. of defects, scrap items, defectives.
Variances given" Tech = 0.05 Part= 0.4 Error= 0.15 Waht si the ratio of the total gage R &R variation? Use straight ANOVA
Variances given" Tech = 0.05 Part= 0.4 Error= 0.15 Waht si the ratio of the total R &R variation? Use straight ANOVA Answer -= 0.333 Total gage R &R variation is technician variance (0.05) which is the reproducibility added to measurement error of 0.15 (repeatability) divided by the toatl variance of 0.6
Variations due to random sampling
Variations due to random sampling 1) Batch-to-batch variation 2) Within-batch variation
Verifying Stability and Normality
Verifying Stability and Normality 1) Common Cause Variation----> process output forms a distribution that is repeatable and stable and predictable over time 2) Special Cause Variation -----> process output not stable and process distribution changes over time and MAY be unstable if the process average/ variation is out of control 3) Chi-square test----used to test the validity of the normality assumption and data is partitioned into data ranges
Virtual Teams- Drawbacks
Virtual Teams- Drawbacks 1) Slow progression of team-building 2) Can't get true commitment 3) Miscommunications
Virtual Teams-3 -Benefits
Virtual Teams--Benefits 1) Enable worldwide access to best people, 2) reduced costs 3) Real-time data sharing
How to create Voice of Customer
Voice of Customer To create a VOC: 1) Id. customers and their needs 2) Analyze reactive data ( complaints, service calls, warranty claims) and then consider proactive approaches (interviews, focus groups, surveys) 3) Convert collected data into customer needs 4) Sort out the most important attributes that the customer wants, that is, information critical to quality characteristics. 5) Get specifications from teh CTQ characteristics.
3 Ways that Stakeholders Impact the health of the Business
Ways that Stakeholders Impact the health of the Business: 1) Stakeholder choose to invest based on expected returns in the near term ( dividends & increased stock price) or longer term (growth) 2) When customer purchase good/service that satisfy their needs, they contribute to the process by positive word-of-mouth, new product ideas, referrals, and additional orders. Negative feedback can harm the company. 3) Supplier/ Customer sets the product/service's value by defining the final specifications----> percieved value is the function of Quality, cost, features, and Availability.
Ways to document Work Instructions
Ways to document Work Instructions 1) Written instructions 2) Checklists 3) Flowcharts 4) Photographs 5) Drawn pictures 6) Videos 7) Electronic screen shots 8) Electronic software-driven process steps
Weibull Distribution
Weibull Distribution Basic assumptions: Family of distributions Can be used to describe many types of data Fits many common distributions (normal, exponential and lognormal) The differing factors are the scale and shape parameters
Weibull Distribution 4 Applications
Weibull Distribution Application 1) Lifetime distributions 2) Reliability applications 3) Failure probabilities that vary over time 4) Can describe burn-in, random, and wear-out phases of a life cycle (bathtub curve)
Weighted Pareto Analysis
Weighted Pareto Analysis ** displays bars whose heights represent the weighted frequencies of the categories. Typical weights are the cost of repair or the loss incurred by the customer. 1) Used to help improvement items with selection of serious problems 2) Assumes that there will be segreation of a significant few from the trivial many 3) Based on number of even occurences and organized by criticality factors
What are Process Maps and Flowcharts Used for?
What are Process Maps and Flowcharts Used for? 1) Provide a visual depiction of their process information for customers and suppliers (SIPOC) 2) Serves as the first step in improving process when used in conjunction with FMEA and value stream mapping.
What are the 2 aspects of quality?
What are the 2 aspects of quality? 1) Quality of design 2) Quality of conformance
What are 2 causes Groupthink?
What causes Groupthink? 1) No public disagreements and doubts expressed in private discussions 2) Fear of group cohesiveness at risk due to conflicts
What are the 2 causes unquestioned acceptance of facts?
What causes unquestioned acceptance of facts? 1) Organizational culture 2) Lack of management by facts
What charting charting process uses data for multiple data for multiple plot point?
What charting charting process uses data for multiple data for multiple plot point? MX bar- MR charts Compare with np charts, run charts, Xbar-R charts.
What control chart is recommended to plot defective using a fixed sample size?
What control chart is recommended to plot defective using a fixed sample size? np chart **p-chart uses a variable number of samples but np uses a fixed number of sample
What control chart pattern best represents an in cntrol process?
What control chart pattern best represents an in o rcntrol process? Random distribution of points on either side fo the cener line.
What could be the benefit of plotting an X-bar and R-chart and discovering that variation is stable but the average is often shifting?
What could be the benefit of plotting an X-bar and R-chart and discovering that variation is stable but the average is often shifting? Knowing that centering the process average might bring the process under control.
What design structure uses the following 4 main phases in the design process? . Clarify the task, Develop conceptual design, Refine design, Generate final detailed design A. Set-based design B. Pugh Analysis C. Critical parameter design D. Systemic Design
What design structure uses the following 4 main phases in the design process? . Clarify the task, Develop conceptual design, Refine design, Generate final detailed design A. Set-based design B. Pugh Analysis C. Critical parameter design D. Systemic Design D- correct---See Primer Section III-28
What distribution is normally used to model rates?
What distribution is normally used to model rates? Poisson Distribution
What factors should be considered when determining which process should be documented?
What factors should be considered when determining which process should be documented? 1) Effect on quality 2) Risk of customer dissatisfaction 3) Statutory and/or regulatory requirements 4) Economic Risk 5) Effectiveness and efficiency 6) Competence of personnel 7) Complexity of process
What graphical data method can show the value of all individual readings?
What graphical data method can show the value of all individual readings? Stem-and- leaf plot Histogram has grouped data. Complex box plot show many data features but individual readings is not among them
What input categories are commonly used in cause-and-effect diagrams?
What input categories are commonly used in cause-and-effect diagrams? Machines, material, and measurement 4 M of cause effect ----machine, material, method, manpower 5M and E method--includes measurement and environment
What is a control chart used for?
What is a control chart used for? Detect non-random variation in the process.
What is an improper action when ensuring data accuracy and integrity?
What is an improper action when ensuring data accuracy and integrity? Removing data based on a firm hunch that is false
What is jidhoka?
What is jidhoka? A device that stops the machine whenever a defective is produced
What is mandatory when conducting a process capability study consistent with PPAP requirements?
What is mandatory when conducting a process capability study consistent with PPAP requirements? Data collected from a significant production run of 300 or more or consecutive pieces.
Define Process Capabiilty
What is process capability 1) Process Capability-------->How do you know if your process is capable? Process Capability Pp measures the process spread vs the specification spread. In other words, how distributed the outcome of your process is vs what the requirements are. a) Note: use Pp & Ppk when you are initially setting up your process. After a process has reached statistical control, use Cp & Cpk.
What is the basic statistical principle of EVOP?
What is the basic statistical principle of EVOP? The ability to recognize small differences through large sample sizes
What is the best reason for having relatively few strategic objectives or goals? A. Difficulties in deploying them horizontally and vertically b. Potential for confusion among employees as to their relative importance c. Problems associated with monitoring and adjusting them properly d. Potential for organizational administration barriers
What is the best reason for having relatively few strategic objectives or goals? A. Difficulties in deploying them horizontally and vertically b. Potential for confusion among employees as to their relative importance c. Problems associated with monitoring and adjusting them properly d. Potential for organizational administration barriers B- correct
What is the biggest risk when developing a product FMEA/ FMEACA? A. Inadequate recommended corrective actions B. Unknown current controls C. Overlooked potential failure modes D. Inadequate number of assigned engineers
What is the biggest risk when developing a product FMEA/ FMEACA? A. Inadequate recommended corrective actions B. Unknown current controls C. Overlooked potential failure modes D. Inadequate number of assigned engineers C- correct
What is the c-chart control limit for 25 readings? 77 61 59 22 54 64 49 54 92 22 75 65 41 89 49 93 45 87 55 33 45 77 40 25 20
What is the c-chart control limit for 25 readings? 77 61 59 22 54 64 49 54 92 22 75 65 41 89 49 93 45 87 55 33 45 77 40 25 20 Answer= 78
What is the danger of using the formula: sigma (t) = R-bar / d2 to determine standard deviation to use in calculating capability index?
What is the danger of using the formula: sigma (t) = R-bar / d2 to determine standard deviation to use in calculating capability index? Factor d2 works when the process is in control and most processes aren't
What is the definition of Takt time? A. it is calculated time element that equals customer demand B. Speed at which parts must be manufactured in order to satisfy demand C. Heartbeat of any lean system D. Application of Kaizen to continuous flow manufacturing
What is the definition of Takt time? A. it is calculated time element that equals customer demand B. Speed at which parts must be manufactured in order to satisfy demand C. Heartbeat of any lean system D. Application of Kaizen to continuous flow manufacturing A- correct
What is the difference between Coifficient of determination and correlation coifficent?
What is the difference between Coifficient of determination and correlation coifficent? Regression analysis == correlation coifficient.
What is the difference between Written procedures and Written Instructions?
What is the difference between Written procedures and Written Instructions? Procedures = describe the process at general level Work Instructions = provide details and step-by-step sequence of activities.
What is the difference between central tendency statistics and Dispersion statistics?
What is the difference between central tendency statistics and Dispersion statistics? Dispersion statistics----how precise data is Central tendency statistics ----how accurate data is
What is the difference between paired and unpaired t test?
What is the difference between paired and unpaired t test? 1) Two-sample t-tests for a difference in mean involve independent samples or unpaired samples. 2) Paired t-tests are a form of blocking, and have greater power than unpaired tests when the paired units are similar with respect to "noise factors" that are independent of membership in the two groups being compared.
What is the difference between process map and flowchart?
What is the difference between process map and flowchart? 1) Process maps = Broad perspective of problems/ opportunities for improvement; Provides additional information about each step (Eg. cost, setup time, cycle time, inventory, types of defects); Can be used to detect non-value-added steps and complexities. 2) Flowcharts = show each step in the process, decision points, inputs, and outputs.; creates a picture of the actual steps in the process or system as it actually operates. Flow charts = analytical tool for monitoring process over TIME; used for training operators and supervisors.
What is the downside of adopting mistake proofing in the work place?
What is the downside of adopting mistake proofing in the work place? In some cases, technical or engineering assistance may be needed especially if the remedies are out of control and capability of floor employees
What is the effect of management tampering with process capability?
What is the effect of management tampering with process capability? Answer= Process capability will deteriorate if management mandates frequent adjustments. Excess adjustments will increas the variation and decrease capable processes
What is the importance of the reaction plan in a control plan?
What is the importance of the reaction plan in a control plan? It describes what will happen if a key variable goes out of control. The actions in a reaction play should be the responsiblity of the people closest to the process
What is the iterative approach to DOE?
What is the iterative approach to DOE? Use of sequential expermentation---> produces more satisfactory results that "one big experiment"
What is the practical difference between the precision/ tolerance ration (P/T ration) and the precision/total variation ration ( P/TV ration) a. P/T ratio and P/TV are practically same. b. P/T ratio gives a better picture of the measurement precision for internal improvement studies while P/TV ratio is better for evaluations relative to specifications. c. P/T ratio gives a better picture of the measurement precision relative to specifications while the P/TV ratio is better fro internal improvement studies. d. The combined P/T and P/TV ratios should equal one in order to achieve a better understanding of the measurement system analysis results.
What is the practical difference between the precision/ tolerance ration (P/T ration) and the precision/total variation ration ( P/TV ration) a. P/T ratio and P/TV are practically same. b. P/T ratio gives a better picture of the measurement precision for internal improvement studies while P/TV ratio is better for evaluations relative to specifications. c. P/T ratio gives a better picture of the measurement precision relative to specifications while the P/TV ratio is better fro internal improvement studies. d. The combined P/T and P/TV ratios should equal one in order to achieve a better understanding of the measurement system analysis results. C= correct----- The denominators of both ratios have different origins. Only in those cases where the capability index is 1 will the P/T ratio be the same. P/T ratio provides better analyses of the measurement system relative to specifications, with the P/TV ratio is more of an internal measure.
What is the practical result of combining a normal random variable and chi-square variable?
What is the practical result of combining a normal random variable and chi-square variable? Small samples can be used to make robust inferences about population means---which describes the t-distribution and its ability to make robust conclusions using small samples
What is the probability of finding no defective items in a random sample of 100 items taken from the output of a continuous process which averages 0.7% defective items?
What is the probability of finding no defective items in a random sample of 100 items taken from the output of a continuous process which averages 0.7% defective items? S= 100 r= 0 P (0.03) The answer can be determined with Poisson table (n) (p)= (100) (0.7)= 0.487
What is the real meaning of single minute concept in SMED? a. that dies will be exchange in 1 min or less b. that dies will exchanged in less than 5 min c. the dies will be exchanged in less that 10 min d.the dies will be exchanged in less that 15 min
What is the real meaning of single minute concept in SMED? a. that dies will be exchange in 1 min or less b. that dies will exchanged in less than 5 min c. the dies will be exchanged in less that 10 min d.the dies will be exchanged in less that 15 min C- correct---less than 10 minutes (not less than 1 min)
What is the relation between resolution III and confounded responses? a. In resolution III experiments, there are no confounded interactions b. In resolution III experiments, only interactions are confounded. c. In resolution III experiments, all factors are confounded. d. In resolution III experiments, main effects and 2 factor interactions are confounded.
What is the relation between resolution III and confounded responses? a. In resolution III experiments, there are no confounded interactions b. In resolution III experiments, only interactions are confounded. c. In resolution III experiments, all factors are confounded. d. In resolution III experiments, main effects and 2 factor interactions are confounded. D= correct Danger of resolution III is that no interactions can be caculated without having them confounded with main effects. Therefore, only main effects can be studied in resolution III
What is the relationship among mean, median, and mode for normal distribution curve?
What is the relationship among mean, median, and mode for normal distribution curve? Mean= Median= Mode
What is the relationship between the sum of the exponents and binomial equation?
What is the relationship between the sum of the exponents and binomial equation? Answer----> Sum of the exponent sof each term after expansions equal to sample size
What is value stream? A. Elimination or reductoin of internal waste B. Minimization of internal, hidden muda C. Map identifying all product related activities D. Value as perceived by the customer
What is value stream? A. Elimination or reductoin of internal waste B. Minimization of internal, hidden muda C. Map identifying all product related activities D. Value as perceived by the customer C- Correct
What percentage of the area under the standard normal curve is included under the curve within 1.5 deviation from zero?
What percentage of the area under the standard normal curve is included under the curve within 1.5 deviation from zero? Area between z= 1.5 and z= -1.5 is 0.9332 - 0.0668 = 0.8664 Answer = 0.8664
What process controls the tempo of the value stream?
What process controls the tempo of the value stream? The pacemaker process. Tempo of the manufacturing stream is controlled by pacemaker process and can be improved
What tool is used to complement Fish-bone diagram?
What tool is used to complement Fish-bone diagram? Brainstorming Cause and effect diagram can be used to solve problems diagnosed via: 1) scatter diagram 2) Force field analysis 3) Pareto diagram
What two organizational steps typically provide feedback to business systems and processes? A. Customer and outputs B. Suppliers and inputs C. Inputs and Outputs D. Outputs and Suppliers
What two organizational steps typically provide feedback to business systems and processes? A. Customer and outputs B. Suppliers and inputs C. Inputs and Outputs D. Outputs and Suppliers A= Correct---> Normally feedback from areas downstream from the business processes. The typical feedback sources are outputs and customers. (Section II-9)
What type of data will a value stream provide?
What type of data will a value stream provide? Changeover and cycle times and work-in-progress inventory
What would occur if quality goals were not part of the strategic plan ? A. No strategic goals would exist B. Not much emphasis on quality C. Total quality effort would not suffer D. Quality Department would still maintain the quality goals
What would occur if quality goals were not part of the strategic plan ? A. No strategic goals would exist B. Not much emphasis on quality C. Total quality effort would not suffer D. Quality Department would still maintain the quality goals B- correct---. Strategic goals could exist without a quality element. D is wrong beacaue quality goals are not strategic in nature.
When Binomial distribution can be used?
When Binomial distribution can be used? 1) When sample greater than 50 (can't use from small sample size) 2) sample size (n) is less than 10% of N or [0.1* N] ; Population size (N) >50 3) Proportion defective is equal to or greater than 0.1
When P (A | B) = P (A) , then : a. Event A and B are independent b. Event A and B are dependent c. Event A and B are mutually exclusive d. Event A and B are compliments
When P (A | B) = P (A) , then : a. Event A and B are independent b. Event A and B are dependent c. Event A and B are mutually exclusive d. Event A and B are compliments B= correct Probability shorthand in the question states the proability of event A, given that event B has occurred, no longer equals the probability of A. this must mean that event B an dthe two evens
When a process is not centered relative to specifications, how is the Cpk affected?
When a process is not centered relative to specifications, how is the Cpk affected? Answer= Cpk is the smalled value of the either Cpk upper or Cpk lower
When a pull system is instituted within an organization, which of the following is stabilized? A. Finished good inventories B. Work-in-progress C. Cycle times D. Pricing
When a pull system is instituted within an organization, which of the following is stabilized? A. Finished good inventories B. Work-in-progress C. Cycle times D. Pricing D- Correct;Key word is stabilized; Generally WIP and finished goods are reduced and cycle times are decreased Customer orders and pricing are stabilized Section III-7
When assess the probability of failure of a product or a system component an index value of 9 is assigned. This means? A. Severity of the failure is high B. High probability of failure c. Control effectiveness is very good D. Over RPN is huge
When assess the probability of failure of a product or a system component an index value of 9 is assigned. This means? A. Severity of the failure is high B. High probability of failure c. Control effectiveness is very good D. Over RPN is huge C- correct; A and C describe the severity and control effectiveness components of RPN
When calculating the sample size for a DOE, one is actually calculating what?
When calculating the sample size for a DOE, one is actually calculating what? Number of replications the number of runs, factors, and blocks are all determined by the planning states of experimental design. Number times each experiment has to be conducted to achieve a robust statistical answer is determined by the number of replications, which indicates the sample size in DOE
When comparing push verses pull concepts, who or what is really doing the pushing? A. Customer B. Cycle Time C. Company management D. Takt time
When comparing push verses pull concepts, who or what is really doing the pushing? A. Customer B. Cycle Time C. Company management D. Takt time C-correct; Push concept is associated with management maximizing production output
When comparing short term machine capability indexes to long term process capability indexes, what can one expect?
When comparing short term machine capability indexes to long term process capability indexes, what can one expect? Answer= Process capability will be a loer number. This question is referring to capability index. In this calculation, a higher number indicates greater capability. The long term process capability would be expected to be a lower number than short term capability
When considering a quality characteristic for process capability calculations, a green belt should consider which of the following: a. Chose the characteristics with the highest process capability index ratios b. Chose a small number of customer defined CTQ characteristics c. Choose only normal characteristics to comply with the normality assumption d. choose all characteristics defined in these procedures and work instructions.
When considering a quality characteristic for process capability calculations, a green belt should consider which of the following: a. Chose the characteristics with the highest process capability index ratios b. Chose a small number of customer defined CTQ characteristics c. Choose only normal characteristics to comply with the normality assumption d. choose all characteristics defined in these procedures and work instructions. B= correct. The chosen characteristic should reflect key product or process quality factors.
Describe the process component and boundaries.
When defining a process, it is important to define its boundaries ---the start and end points. Boundaries are defined by organizational structure, geography, and ect The components of a process are called subprocesses
When describing a process being considered for cycle time reduction, the existing process flows are known as? a. Key operation points (KOPS) b. Dynamic Pull chart c. Current state map d. Activity network diagram
When describing a process being considered for cycle time reduction, the existing process flows are known as? Current State Map
When designing TPM, why would BITE (built-in test equipment) be of advantage?
When designing TPM, why would BITE (built-in test equipment) be of advantage? In fault isolation.
When is it economical to permit an X-bar chart to go out of control ?
When is it economical to permit an X-bar chart to go out of control ? The control limits are appreciably less than the specification limits. Since X-bar chart represents average data, individual reading may be in control and out of tolerance. Only when 6sigma is appreciably less than the specification limits will out of control conditions on the X-bar chart make economic sense
When performing calculation on sample data: a. continuous relative frequency graph is created b. rounding the data has no effect on the mean and standard deviation c. coding the data has no effect on the mean and standard deviation d. coding the data has effect on both mean and standard deviation
When performing calculation on sample data: a. continuous relative frequency graph is created b. rounding the data has no effect on the mean and standard deviation c. coding the data has no effect on the mean and standard deviation d. coding the data has effect on both mean and standard deviation D= correct. Coding data will affect the mean to the extent that mean must be uncoded fro reporting purposes.
When selecting and scaling the process input variables for an experiment, which of the following is a desirable approach? a. include as many factors as possible b. set factor levels at extreme levels c. combine process measurement responses when possible d. be bold, but not foolish, in selecting high and low factor levels.
When selecting and scaling the process input variables for an experiment, which of the following is a desirable approach? a. include as many factors as possible b. set factor levels at extreme levels c. combine process measurement responses when possible d. be bold, but not foolish, in selecting high and low factor levels. D= correct Factor levels should be set at practical levels If two or more measurement responses are combined, the the important factor (between them) my remain hidden.
When setting quality department short-term objectives, the most important factor to consider is that: A. Short-term objectives address all improvement opportunities B. Departmental objectives include completion dates C. Milestones are established for each objective D. Quality objectives support the organizational objectives
When setting quality department short-term objectives, the most important factor to consider is that: A. Short-term objectives address all improvement opportunities B. Departmental objectives include completion dates C. Milestones are established for each objective D. Quality objectives support the organizational objectives D= correct When establishing departmental objectives, the most important factor is that they support the organizational objectives. Resources for completion of the departmental objectives would then be easier to obtain, and when completed, the organization will have made progress toward completing its objectives. Well constructed objectives do include completion dates and measures of achievement, but they are not the most important factors in the wording of this question . Section II-37
When should project measures be determined?
When should project measures be determined? Project measures should be identified during the initial planning stages and be refined as project progresses.
When the natural process limits are compared with specification limits, when would you: Accept Losses
When the natural process limits are compared with specification limits, when would you: Accept Losses--> After centering process and reducing variability, will be left with scrap and rework as losses.
When the natural process limits are compared with specification limits, when would you: Center the process
When the natural process limits are compared with specification limits, when would you: Center the process---> When you need to bring the bulk of the product within the specification limits or when the process spread is same as the specification limits spread
When the natural process limits are compared with specification limits, when would you: Change specification limits
When the natural process limits are compared with specification limits, when would you: Change specification limits---> When specification limits are too tight and need to be relaxed or modified
When the natural process limits are compared with specification limits, when would you: Do Nothing?
When the natural process limits are compared with specification limits, when would you: Do Nothing ----> When process limits fall within specification limits
When the natural process limits are compared with specification limits, when would you: Reduce Variability
When the natural process limits are compared with specification limits, when would you: Reduce Variability ---> When it is possible to partition the variation (within piece, batch-to-batch) and work on the largest offender
When the natural process limits are greater than the specification range, which of the actions involves the customer? a. changing the specifications b. centering the process c. reducing the variability d. accepting the losses
When the natural process limits are greater than the specification range, which of the actions involves the customer? a. changing the specifications b. centering the process c. reducing the variability d. accepting the losses A= correct. All are good options but accepting looses is not desirable.
When the term "pull " is used in lean thinking. Who's doing the pulling? a. Downstream operations b. takt time c. customer d. cycle time
When the term "pull " is used in lean thinking. Who's doing the pulling? a. Downstream operations b. takt time c. customer d. cycle time C- correct
When to use Weibull Distribution?
When to use Weibull Distribution? Mainly for reliability data when the underlying distribution is unknown; Estimates the shape parameter beta an mean time between failures or failure rates
When used together for variable data. which pair of quantities is useful in preparing control charts?
When used together for variable data. which pair of quantities is useful in preparing control charts? X-bar R- chart !! R, sigma measure dispersion ALQ, p-bar , p-chart and n-chart ---attribute data
When using Poisson as an approximation to the binomial, which of the following conditions apply for the best approximation?
When using Poisson as an approximation to the binomial, which of the following conditions apply for the best approximation? Poisson is an approximation to the binomial distribution when the probability of occurrence is equal to or less than 0.1 and the sample size is large. Smaller the fraction defective and the larger the sample size, the better the approximation.
When would Cp and Cpk be equal?
When would Cp and Cpk be equal? When the process is perfectly centered.
Which DMAIC is where root cause is found?
Which DMAIC is where root cause is found? Analysis
Which IDOV phase defines overall product requirements, quantifies marketing information and customer feedback, and creates the first set of CTQ? a. identity b. design c. optimize d. validate
Which IDOV phase defines overall product requirements, quantifies marketing information and customer feedback, and creates the first set of CTQ? a. identity b. design c. optimize d. validate A- correct ( III-page25)
Which MSA methods allows the interaction between operators and parts to be determined? a. ANOVA method b. Average and Range method c. Interaction method d. Range method
Which MSA methods allows the interaction between operators and parts to be determined? a. ANOVA method b. Average and Range method c. Interaction method d. Range method A= correct; ANOVA method is the most accurate method for calculating repeatability and reproducibility. Not only doe it include the other two formal methods (Range method and Average and Range method) but it also allows for a determination ofthe interaction between appraisers and parts. Interaction method is a distractor
Which distribution is most appropriate for modeling the number of surface defects on a drive?
Which distribution is most appropriate for modeling the number of surface defects on a drive? Poissian distribution--because it modls rates such as the number of defects per disk drive or number of defect per autonobile and is a discret distribution with its expected value equal to its variance
Which lean enterprise technique supports videotaping of a segment of operations as helpful? A. SMED B. TPM C. Takt D. FIFO
Which lean enterprise technique supports videotaping of a segment of operations as helpful? A. SMED B. TPM C. Takt D. FIFO A-correct--timing of rapid die change out benefits from video taping the process and running tape in slow motion to see areas of delay
Which measure of variability is independent of exact value of every measurement? a. Mean deviation b. variance c. range d. standard deviation
Which measure of variability is independent of exact value of every measurement? a. Mean deviation b. variance c. range d. standard deviation C= correct; Variance, mean, deviation, and st. deviation requires the exact value for every measurement. Range requires the exact values for highest and lowest measurements only.
Which of the following are DFSS techniques? A. IDOV and DMADV B. Kaizen and Kanban C. SPC and CWQC D. DPIV and KPOV
Which of the following are DFSS techniques? A. IDOV and DMADV B. Kaizen and Kanban C. SPC and CWQC D. DPIV and KPOV A- correct ( Section III page 25/26)
Which of the following are defect elimination and detection techniques? A. Vendor certificate compliance B. Standard work and TPM C. Source Inspection and Operator self checks D. Non-value added activities and TOC
Which of the following are defect elimination and detection techniques? A. Vendor certificate compliance B. Standard work and TPM C. Source Inspection and Operator self checks D. Non-value added activities and TOC C- correct
Which of the following are value added activities? A. Mistaking proofing a process B. Transporting parts quickly C. Having extra inventory to meet customer demands d. Efficient internal repair processes
Which of the following are value added activities? A. Mistaking proofing a process B. Transporting parts quickly C. Having extra inventory to meet customer demands d. Efficient internal repair processes A- correct--"do things right the first time"
Which of the following characterize the muda of waiting? a. inefficient use of the human body b. inspection and rework c. uneven schedules and unnecessary meetings d. excessive parts and raw materials
Which of the following characterize the muda of waiting? a. inefficient use of the human body b. inspection and rework c. uneven schedules and unnecessary meetings d. excessive parts and raw materials C- correct A= muda of extra motion; B and Dis muda of processing and inventory
Which of the following conditions are driving companies to adopt a lean approach? a. Fixed performance requirements b. Eliminating waste from the process C. Increasing total costs D. Decreasing capacity
Which of the following conditions are driving companies to adopt a lean approach? a. Fixed performance requirements b. Eliminating waste from the process C. Increasing total costs D. Decreasing capacity B- correct (section III- 2/10) ; the opposite are true for C and D
Which of the following distribution have their x- axis starting at zero a. normal and t b. normal and chi-square c. chi-square and F d. F and t
Which of the following distribution have their x- axis starting at zero a. normal and t b. normal and chi-square c. chi-square and F d. F and t C= correct. Negative values have no meaning in either of these two distributions.
Which of the following forms of muda affects people more than product quality? a. Overproduction b. Excess Inventory c. Waiting d. Transport
Which of the following forms of muda affects people more than product quality? a. Overproduction b. Excess Inventory c. Waiting d. Transport C- correct
Which of the following is NVA? A. Design reviews B. Vendor assessments C. Inventory reductions D. Receiving inspection to ensure incoming quality
Which of the following is NVA? A. Design reviews B. Vendor assessments C. Inventory reductions D. Receiving inspection to ensure incoming quality D- correct---because vendor should be sending quality product
Which of the following is TOC principle ? a. maximizing throughput and continuous improvement b. most system process steps are optimized c. management must direct all local activities d. break-through improvement required
Which of the following is TOC principle ? a. maximizing throughput and continuous improvement b. most system process steps are optimized c. management must direct all local activities d. break-through improvement required A- correct (theory of Constraints) --System optimization can't be the sum of optimum steps since sub-processes are interdependent
Which of the following is a measure of marketplace response? A. Customer Courtesy ratings B. Cost of Quality C. Percentage of defects generated D. Reduction in product or service Variation
Which of the following is a measure of marketplace response? A. Customer Courtesy ratings B. Cost of Quality C. Percentage of defects generated D. Reduction in product or service Variation A= Correct......Remaining are measurement of resource usage
Which of the following is a normally accepted control chart interpretation rule violation? a. 5 or more consecutive points out of 20 above or below the center line b. 6 or more consecutive points, upward or downward, in more than 20 plots points. c. 2of the 5 consecutive points in zone 3 d. 10 points in a row in zone 1
Which of the following is a normally accepted control chart interpretation rule violation? a. 5 or more consecutive points out of 20 above or below the center line b. 6 or more consecutive points, upward or downward, in more than 20 plots points. c. 2of the 5 consecutive points in zone 3 d. 10 points in a row in zone 1 B= correct. The zone 1 violoation normally requires 15 point in row. XI-page 32
Which of the following is an acceptable reason for the deployment of 6 sigma projects? A. Focus on costs savings and customer satisfaction B. Focus on quality planning, control, and improvement C. Focus on PDCA/ PDSA cyle D. Focus on Design Improvements
Which of the following is an acceptable reason for the deployment of 6 sigma projects? A. Focus on costs savings and customer satisfaction B. Focus on quality planning, control, and improvement C. Focus on PDCA/ PDSA cyle D. Focus on Design Improvements A= correct B= Juran's triology and C describes a problem-solving approach
Which of the following is considered muda? A. Design reviews B. Level scheduling of work C. Checking a die before installation D. Breakdowns in machinery
Which of the following is considered muda? A. Design reviews B. Level scheduling of work C. Checking a die before installation D. Breakdowns in machinery A- correct---> Design reviews are part of continuous improvement and are part of value-added activity
Which of the following is likely to create process shifts? a. new measuring device b. gradual tool wear and heat build up c. reduction in defective level due to kaizen technique d. small increase in state gasoline taxes
Which of the following is likely to create process shifts? a. new measuring device b. gradual tool wear and heat build up c. reduction in defective level due to kaizen technique d. small increase in state gasoline taxes A= correct; Process shift is due to rapid shifts in the process pattern being plotted like a change in crew (machine setting) or change in method/ measuring device
Which of the following is necessary assumption to validate the meaning of the standard deviation of the measurement variability? a. Measurement errors are independent b. Measurement scale is normally distributed c. Measurement errors are independent of the operators involved in the study d. Measurement errors are skewed in the direction of nornality
Which of the following is necessary assumption to validate the meaning of the standard deviation of the measurement variability? a. Measurement errors are independent b. Measurement scale is normally distributed c. Measurement errors are independent of the operators involved in the study d. Measurement errors are skewed in the direction of normality A= correct The valid assumptions for standard deviation due to the measurement variability are: (1) Measurement errors are independent (2) Measurement errors is normally distributed (3) Measurement errors are independent on the magnitude of the measurement.
Which of the following is preventative technique? A. Rework due to poor molding B. Performing design validation C. In-process inspection D. Re-tooling because of engineering changes
Which of the following is preventative technique? A. Rework due to poor molding B. Performing design validation C. In-process inspection D. Re-tooling because of engineering changes B- correct; Other answers are forms of muda
Which of the following is the most necessary resource requirement needed to achieve strategic goals? a. Infrastructure and support of the projects b. Large training department c. Administration of programs d. Few tactical supporting goals
Which of the following is the most necessary resource requirement needed to achieve strategic goals? a. Infrastructure and support of the projects b. Large training department c. Administration of programs d. Few tactical supporting goals A-correct 0---section ii pag 6/9
Which of the following is true in regards to blocking? a. A block is a dummy factor which doesn't interact with real factors b. A blocking factor has 2 levels c. The experiment is a subdivision of the block d. Blocks permit full randomization of runs
Which of the following is true in regards to blocking? a. A block is a dummy factor which doesn't interact with real factors b. A blocking factor has 2 levels c. The experiment is a subdivision of the block d. Blocks permit full randomization of runs A= correct Blocking is used to compensate when production processes restrict randomization of runs. for example, assume an experimental factor is a temperature, an dis set of 3 levels. If it is very difficult to move the temperature between the 3 levels the experiment could be blocked into 3 groups: low, medium, high temperature. Each block of trials would be run together. To compensate for not running the trials in random order, the bolck is a dummy variable. Dummy variable can have may levels as desired.
Which of the following organizations is ready for DFSS approach? a. Organization has recently become ISO 9001 certified b. First full-time black belt was recently hired and oriented with the organization c. After many successful six sigma projects the rate of improvement has slowed d. New CEO has strong engineering background and wants change
Which of the following organizations is ready for DFSS approach? a. Organization has recently become ISO 9001 certified b. First full-time black belt was recently hired and oriented with the organization c. After many successful six sigma projects the rate of improvement has slowed d. New CEO has strong engineering background and wants change C- Correct-- ISO 9001, or other quality system certification (answer A) provides evidence of decent level of quality organization but it does not say anything about improvement projects and current quality levels
Which of the following statement is most applicable to trend analysis? A. experience is required for proper interpretation b. bar charts are more informative than run charts c. most applications should be reflected as an improvement percentage d. An improving trend is an indication of corporate survival
Which of the following statement is most applicable to trend analysis? A. experience is required for proper interpretation b. bar charts are more informative than run charts c. most applications should be reflected as an improvement percentage d. An improving trend is an indication of corporate survival A= correct b and C may be correct or incorrect dependent upon the subject being charted. (D) is correct but not ALWAYS true. Experience and recognition of fallacies are important in trend analysis. VI--33/34
Which of the following statements can factually be made regarding the objective " Quality will be improved next year"? A. It describe the measure of quality B. This statement has a defined ending date C. How the improvements will be made are stated. D. It is easy to determine the new quality level
Which of the following statements can factually be made regarding the objective " Quality will be improved next year"? A. It describe the measure of quality B. This statement has a defined ending date C. How the improvements will be made are stated. D. It is easy to determine the new quality level B- correct!
Which of the following statements is true about Latin Square design? a. minimizes the chance of factor confounding b. does not allow for the effects of interaction in design c. eliminates the need to ensure that the effects of interaction are additive d. useful because the underlying distribution does not need to be normal
Which of the following statements is true about Latin Square design? a. minimizes the chance of factor confounding b. does not allow for the effects of interaction in design c. eliminates the need to ensure that the effects of interaction are additive d. useful because the underlying distribution does not need to be normal B= correct Latin square designs are highly fractional factorial experiments which permit an analysis of main effects only. Interaction effects cannot be determined; they are confounded with the main effect results.
Which of the following statements is true about a sample of 10 units taken from a population? a. standard deviation is greater than the variance b. range is greater than standard deviation c. sigma estimate cannot be determined d. no estimate of population average is possible
Which of the following statements is true about a sample of 10 units taken from a population? a. standard deviation is greater than the variance b. range is greater than standard deviation c. sigma estimate cannot be determined d. no estimate of population average is possible B= correct C and D are untrue Variance is standard deviation squared
Which of the following statistical term statements is correct? a. parameters come from samples b. samples come from statistics c. statistics come from samples d. populations comes from statistics
Which of the following statistical term statements is correct? a. parameters come from samples b. samples come from statistics c. statistics come from samples d. populations comes from statistics C= correct. Parameters are tur population values, most often unknown, while statistics are population estimates that come from samples.
Which of the following would be a device associated with visual factory? A. Standard work B. Andon board C. Queue time D. Work Cell
Which of the following would be a device associated with visual factory? A. Standard work B. Andon board C. Queue time D. Work Cell B- correct
Which of the following would be considered a strategic quality goal? A. Commitment to customer B. Reducing the scrap rate in the finishing department by 1% C. Improved performance inspection check on work in process. D. Training 6 green belts in statistical techniques this quarter
Which of the following would be considered a strategic quality goal? A. Commitment to customer B. Reducing the scrap rate in the finishing department by 1% C. Improved performance inspection check on work in process. D. Training 6 green belts in statistical techniques this quarter A- Correct---Key being Quality
Which of the number sets are mutually exclusive? a. 1,2,3, and 2,4,6, b. 2,4,6 and 1,3,5, 7 c. 1,3,5,7 and 5,7,8.9 d. 1,2,3,4,5,6,7,8, snf 3,8
Which of the number sets are mutually exclusive? a. 1,2,3, and 2,4,6, b. 2,4,6 and 1,3,5, 7 c. 1,3,5,7 and 5,7,8.9 d. 1,2,3,4,5,6,7,8, and 3,8 B= correct; Mutually exclusive is when they have no elements in common
Which of the tasks is value-added? A. Appropriate product development process B. Reworking parts to meet customer requirements C. MRB meetings D. Efficient material handling of customers
Which of the tasks is value-added? A. Appropriate product development process B. Reworking parts to meet customer requirements C. MRB meetings D. Efficeint material handling of customers A- correct
Which one of the following is single factor experiment containing specific nuisance factors? a. Graeco- Latin square b. Fractional Factorial c. Latin square d. Mixture design
Which one of the following is single factor experiment containing specific nuisance factors? a. Graeco- Latin square b. Fractional Factorial c. Latin square d. Mixture design C= correct. In this case, there are 2 factors that are not being studied, bu they will probably have an effect on the final outcome. This kind of blocking is done by means of Latin square design. Graeco Latin square design implies 3 and not 2 blocking factors. Fractional factorial studies all factors involved.
Which quality tool displays large amounts of numeric data to show a static picture of process behavior?
Which quality tool displays large amounts of numeric data to show a static picture of process behavior? Histogram
Which six sigma steps comes last? A. Define project goals and customer needs specification B. Analyze the process options C. Verify and validate design D. Develop design details for producing customer needs
Which six sigma steps comes last? A. Define project goals and customer needs specification B. Analyze the process options C. Verify and validate design D. Develop design details for producing customer needs C- corrrect ; DMADV
Which type of distribution is closely related to expotential distribution?
Which type of distribution is closely related to expotential distribution? Poissian distribution
While plotting a control chart, it is noted that two of the last 3 points are than 2 sigma, four out of the last points are greater than 1 sigma, and 8 successive points are on one sideof the center lime. What should one do? a. stop the process immediately b. take more readings and continue to plot c. write a discrepancy notice to the supervisor d. investigate to determine what has changed
While plotting a control chart, it is noted that two of the last 3 points are than 2 sigma, four out of the last points are greater than 1 sigma, and 8 successive points are on one sideof the center lime. What should one do? a. stop the process immediately b. take more readings and continue to plot c. write a discrepancy notice to the supervisor d. investigate to determine what has changed D= correct Using any set of interpretation rules, there has been a significant change in the process. If an X-bar chart or attribute chart is being plotted, there is evidence of a shift, trend, or drift in the process. If an R-chart is being charted, the variability has changed significantly.
6 types of stakeholders in a process?
Who are stakeholders in a process? 1) Process operations and managers form all shifts 2) Process customers, internal and external 3) Process suppliers, internal and external 4) Process design personnel 5) Maintenance personnel 6) Others impacted in some way by process change
Who coined the term Total Quality management? A. Feigenbaum B. Deming C. Juran D. Shewart
Who coined the term Total Quality management? A. Feigenbaum B. Deming C. Juran D. Shewart A---Feignebaum termed both TQM and TQC
Who develops the Project charter?
Who develops the Project charter? Can be Developed by EITHER: 1) Top Management OR Team 2) Either way, Top Management's endorsement is critical for giving the team the support and direction it needs. Why Top Management's endorsement important? ---> 1) Teams need to know what top management expects of them. 2) Team must have the authority, permission, and blessing of each level of management to operate, conduct research, implement changes to achieve results
Who has ultimate responsiblity initially for the control plan?
Who has ultimate responsiblity initially for the control plan? Green belt
Who is the creator of the control chart? A. Deming B. Shewart C. Juran D. Ishikawa
Who is the creator of the control chart? A. Deming B. Shewart C. Juran D. Ishikawa D=corect
Who was the creater of DOE? A. Deming B. Juran C. Ishikawa D. Taguchi
Who was the creater of DOE? A. Deming B. Juran C. Ishikawa D. Taguchi D= correct---> Taguchi presented a cook book approach
Why DFSS called future of six sigma? A. Few remaining DMAIC project available in most companies B. DFSS roadmaps are more attractive than DMAIC tools C. DFSS better serves the current innovation initiatives of many companies D. DMAIC project do not achieve six sigma levels without DFSS
Why DFSS called future of six sigma? A. Few remaining DMAIC project available in most companies B. DFSS roadmaps are more attractive than DMAIC tools C. DFSS better serves the current innovation initiatives of many companies D. DMAIC project do not achieve six sigma levels without DFSS C- Correct; In both private and govt sector express the need for whole strategies based on systematic innovation. DFSS roadmaps have the potential to become the center of such innovation initiatives. There are plenty of DMAIC projects in companies.
Why are processes measured?
Why are processes measured? 1) Process input variables are measured to control variation in output responses. 2) The effects of variations of input on output are explored using tools (eg. scatter diagrams, relationship matrices, fishbone diagram) 3) Through understanding of process inputs and outputs is key to step for process improvements.
Why are scatter diagrams useful in problem solving?
Why are scatter diagrams useful in problem solving? They show relationships between variables
Why are work procedures and work instructions a necessity?
Why are work procedures and work instructions a necessity? Worldwide demand for ISO 9001 compliance makes necessity for work instructions and work procedures. ISO requires that internal procedures to control nonconforming products so the it is presented from inadvertent use or installation. (Assigned to Quality Dept) They help drive consistency in business and manufacturing. Consistent approach to process management helps yield improvements, root cause analysis and traceability.
Why has six sigma been so successful for many organizations? A. Bottom line results are enhanced B. A +/- sigma shift is included C. An undisciplined approach is used D. Sound statistical approaches are eliminated
Why has six sigma been so successful for many organizations? A. Bottom line results are enhanced B. A +/- sigma shift is included C. An undisciplined approach is used D. Sound statistical approaches are eliminated A-correct
Why is PCDA more accepted by most American Teams? A. It is the natural way that most people already approach problmes b. It was promoted by an American, Deming C. Widely used in Japan with sucess D. Requires much less work than other improvement techniques
Why is PCDA more accepted by most American Teams? A. It is the natural way that most people already approach problmes b. It was promoted by an American, Deming C. Widely used in Japan with sucess D. Requires much less work than other improvement techniques A-correct
Why is important for process improvement teams to be composed of stakeholders? (4 reasons)
Why is important for process improvement teams to be composed of stakeholders? 1) Stakeholders have the best knowledge base about the process
Why is measurement system analysis important?
Why is measurement system analysis important? 1) All data from process is filtered via measurement system 2) Measurement system analysis is the most cost-effective way to reduce variation
Why is six sigma called TQM on steriod? A. Because of the extensive training element requirement B. Because of the inclusion of statistical and lean tools C. Because of the heavy impact of top management support D. Because of the impact of cost savings on the bottom line.
Why is six sigma called TQM on steriod? A. Because of the extensive training element requirement B. Because of the inclusion of statistical and lean tools C. Because of the heavy impact of top management support D. Because of the impact of cost savings on the bottom line. B- Correct----> Steriod quote comes from the inclusion of statistical items such DOE, DFSS, statistical analysis, ect. and certain maufacturing tools
Why is the normality assumption essential to the interpretation of the capability index?
Why is the normality assumption essential to the interpretation of the capability index? Answer= Because the normal distribution always has a mean equal to zero The meaning of the capability index comes from the fact that the specification limits is being compared with 99.73% of all possible outputs for the process represented by a process spread of 6 standard deviations. The comparison is meaningless if the process distribution is not normal.
Why should an X-MR chart be used?
Why should an X-MR chart be used? For destructive testing process
Why would one choose to plot run charts instead of other more powerful variable charting options?
Why would one choose to plot run charts instead of other more powerful variable charting options? There is a limited amount of single point data Atribute data and short runs doen't make sense for this question. Ongoing automatic determination of sigma is a reason to consider X-bar-sigma charts. Limited data cane asily be plotted in run charts. Theses are not as powerful as some other options but are the best choice for limited data.
Wiebull Distribution
Wiebull Distribution 1) Locational parameter where β >0 is the shape parameter and δ > 0 is the scale parameter 2) Has variety of shapes 3) Reliability engineering model
With Gage R & R, the error is usually due to what?
With Gage R & R, the error is usually due to what? Error can be determined if they are due to measurement errors.
Womack stated that perfection in a lean organization should be: A. Specified b. Pursued C. Identified D. Pulled
Womack stated that perfection in a lean organization should be: A. Specified b. Pursued C. Identified D. Pulled B- Correct
Work Breakdown Structure Time Constrained Projects vs. Resource-Constrained Projects
Work Breakdown Structure 1) Plan that expands the project (Statement of Work) into a detailed listing of activities needed to complete the project 2) Project Team leader assigns tasks/ responsibilities and creates the work breakdown structure 3) Predececsor Event---> an activity that must be completed before another begins 4) If time constraints are fixed, then resource constraints must be flexible to accommodate variations in project.---> Contract may impose penalties for each day that project is late and therefore time delays require offstting increase in resources and costs to keep the original deadline 5) Resource-Constrained (equipment / manpower) Projects-----> If shared resources, then must schedule and coordinate resources---> Objective is to meet the project deadline without exceeding resource limits
Work Instructions
Work Instructions 1) Procedures describe the process at general level, while work instructions provide details and step-by-step sequence of activities. 2) Flow charts may be used with work-instructions to show relationships of process steps. 3) Controlled copies of work instructions are kept in the area where the activities are performed. 4) Level of detail in the work instruction should be appropriate for background, experience, and skill of the personnel. 5) Wording and terminology should match that used by those doing the work.
Written Procedures
Written Procedures 1) ISO 9001 ---States that internal procedures shall control nonconforming product so that it is prevented from inadvertent use of installation. ------> Quality Department Responsibility but functions carried out by multiple departments 2) Procedure should be developed by those having responsibility for the process on interest.
X-Bar & R charts
X-Bar & R charts 1) Best for short runs ---> 3-10 pieces without adjustment 2) Inflated A2 and D4 values are used to establish control limits 3) Small runs with limited amount of data ---> use X and MR charts 4) Moving range (MR) = piece-to-piece variability 5) X= individual data values 6) As data points increases the calculated process capability will approach true capability
What is Z-score?
Z-Score 1) Measure of how many standard deviations below or above the population mean a raw score is. 2) AKA. standard score and it can be placed on a normal distribution curve. 3) Z-scores range from -3 std devs (which would fall to the far left of the normal distribution curve) to +3 std devs (which would fall to the far right of the normal distribution curve). 4) In order to use a z-score, must know the mean μ and the population standard deviation σ.
Which Inference Test? Single sample mean, Standard Deviation of population known
Z-test: Single sample mean, Standard Deviation of population known
Process Specification Difference between Voice of Process & Voice of Client
b) Process has 2 specifications; [(Limit (LSL) , (USL)] Voice of the Client.=The difference between the two is the specification spread; Voice of the Process. =Process spread =distance b/w the highest and lowest value
p-test
p-test When testing a claim about population proportion and we have a fixed number of independent trials with constant probabilities, and each trial has two outcome possibilities (binomial experiment), we can use p-test. 1) When np < 5 or n (1-p) < 5 ---> use binomial distribution to test hypothesis 2) When np > / = 5 or n (1-p) > / = 5 ---> binomial distribution of sample proportions can be approximated by normal distribution
p-value definition
p-value definition: Probability of getting a value of the sample test statistic that is at least as extreme as the one found from the sample data 1) Small p-value ---> Hypothesis is False 2)
t-test
t-test A statistical examination of two population means. A two-sample t-test examines whether two samples are different and is commonly used when the variances of two normal distributions are unknown and when an experiment uses a small sample size. A t-test's statistical significance indicates whether or not the difference between two groups' averages most likely reflects a "real" difference in the population from which the groups were sampled.
Which Inference Test? Single sample mean, Standard Deviation of population unknown
t-test: Single sample mean, Standard Deviation of population unknown