Chpt 3 CHPT
c-chart
- Measures the number of defects when more than one defect can be present in a service or product OR c-charts - A chart used for controlling the number of defects when more than one defect can be present in a service or product. UCLc= C+Z(ROOT C) LCLc= C-Z(ROOT C)
p-chart
- Measures the proportion of defective services or products generated by the process -p-charts are used for controlling the proportion of defective services or products generated by the process. The standard deviation is σp=ROOT(P(1-p) /N) UCLp=P+Zσp LCLp=P-ZσP P=TOTAL DEFECTIVES/TOTAL # OF OBSERVATIONS
R-Chart
- Measures the variability of the process UCLr=D4R LCLr=D3R
𝒙 ̅-Chart
- Measures whether the process is generating output, on average, consistent with a target value UCLx=X+A2R LCLx=X-A2R
Process Capability
- The ability of the process to meet the design specification for a service or product Nominal Value -A target for design specifications Tolerance -An allowance above or below the nominal value
𝒙 ̅
= mean
xi
= observation of a quality characteristic (such as time)
n
= total number of observations
Training workers to do their jobs properly and working with suppliers to improve the quality of material they supply to you are examples of A. prevention costs. B. internal failure costs. C. external failure costs. D. appraisal costs.
A
Six Sigma
A comprehensive and flexible system for achieving, sustaining, and maximizing business success by minimizing defects and variability in processes OR Goal of achieving low rates of defective output by developing processes whose mean output for a performance measure is +/- six standard deviations (sigma) from the limits of the design specifications for the service or product.
Total Quality Management
A philosophy that stresses three principles (customer satisfaction, employee involvement and continuous improvement) for achieving high level of process performance and quality
Quality
A term used by customers to describe their general satisfaction with a service or product
Which of the following is considered one of the four major cost of quality categories? A.lost goodwill B.defects C.postponement D.appraisal
APPRAISAL
Type II error
An error that occurs when the employee concludes that the process is in control and only randomness is present, when actually the process is out of statistical control
Type I error
An error that occurs when the employee concludes that the process is out of control based on a sample result that fails outside the control limits, when it fact it was due to pure randomness
Defect
Any instance when a process fails to satisfy its customer
In acceptance sampling, if the sample passes the test then A. the entire quantity is returned to the supplier. B. the entire quantity of items is accepted. C. the remaining quantity of items is subjected to 100 percent inspection. D. the supplier is producing 100% high quality output.
B
Most experts on the costs of poor process performance and quality estimate losses in the range of ________ percent of gross sales for defective or unsatisfactory products. A. 10 to 20 B. 20 to 30 C. 30 to 40 D. 0 to 10
B
A process failure that results in the process's inability to meet advertised performance standards violates which of the five definitions of quality? A. psychological impressions B. value C. conformance to specifications D. fitness for use
C
The PDCA cycle illustrates A. the improvement in costs associated with implementation of ISO 9000. B. the type of chart to make for each process control situation. C. continuous improvement. D. the rise and fall of points in a process that is exhibiting only common cause variation.
C
Categories of Variation
Common cause - The purely random, unidentifiable sources of variation that are unavoidable with the current process Assignable cause - Any variation-causing factors that can be identified and eliminated
Customer Satisfaction
Conformance to Specifications Value Fitness for Use Support Psychological Impressions
Prevention costs
Costs associated with preventing defects before they happen
Appraisal costs
Costs incurred when the firm assesses the performance level of its processes
Internal Failure costs
Costs resulting from defects that are discovered during the production of a service or product
External Failure costs
Costs that arise when a defect is discovered after the customer receives the service or product
Process Capability Index (Cpk)
Cpk=MINIMUM OF ((X-LOWER SPECIFICATION)/3σ), (UPPER SPECIFICATION-X/3σ) An index that measures the potential for a process to generate defective outputs relative to either upper or lower specifications.
Employee Involvement
Cultural Change Quality at the Source Teams Employee Empowerment Problem-solving teams Special-purpose teams Self-managed teams
A firm's internal program in employee involvement includes which of the following considerations? A. Supplier management B. Psychological impressions C. Product availability D. Defining who the customer is
D
TQM stresses three principles for achieving high levels of process performance and quality. Which of the following is one of them? A. life-long employment B. management leadership C. continuous employee improvement D. customer satisfaction
D
Which of the following is an element of a deceptive business practice that presents a major concern for service or product quality? A.The provider conceals the truth based upon what is actually known to the provider. B.The transaction is intended to generate a disproportionate economic benefit to the provider at the expense of the customer. C.The conduct of the provider is intentional and motivated by a desire to exploit the customer. D.All of the above.
D
Complete Inspection (SPC)
Inspect each service or product at each stage of the process for quality
Continuous Improvement
Kaizen Problem-solving tools Plan-Do-Study-Act Cycle
Variation of Outputs
No two services of products are exactly alike because the processes used to produce them contain many sources of variation, even if the processes are working as intended.
Variable Control Charts
R-Chart 𝒙 ̅-Chart
Sampling
Sample Size Time between successive samples Decision rules that determine when action should be taken
Acceptance Sampling
The application of statistical techniques to determine if a quantity of material from a supplier should be accepted or rejected based on the inspection or test of one or more samples.
SPC Statistical Process Control
The application of statistical techniques to determine whether a process is delivering what the customer wants.
Acceptable Quality Level
The quality level desired by the consumer.
Process Capability (Cp)
The tolerance width divided by six standard deviations. Cp=(UPPERSPECIFICATION-LOWER SPECIFICATION)/6σ
Control Chart
Time-ordered diagram that is used to determine whether observed variations are abnormal Controls chart have a nominal value or center line, Upper Control Limit (UCL), and Lower Control Limit (LCL)
IF STANDARD DEVIATION OF THE PROCESS IS KNOWN THERE IS A DIFFERENT X-CHART FORMULA
UCLx=X+Zσx LCLx=X-Zσx σx= σ/ROOT n σ= standard deviation of the process distribution n= sample size x= central line of the chart z= normal deviate number
Performance Measurements (SPC)
Variables - Service or product characteristics that can be measured Attributes - Service or product characteristics that can be quickly counted for acceptable performance
The ISO 14001:2004 standards require documentation of a firm's environmental program. Which component requires a plan to improve performance in resource use and pollutant output? A. Environmental Performance Evaluation B. Environmental Management System C. Life-Cycle Assessment D. Environmental Labeling
b
Which of the following is one of the seven major criteria for the Baldrige award? A. industry standing B. results C. vendor management D. process expertise
b
Which of the following statements about acceptance sampling is true? A. Acceptance sampling eliminates the chance of accepting bad-quality materials. B. Acceptance sampling is the application of statistical techniques to determine if a quantity of material from a supplier should be accepted or rejected. C. Acceptance sampling limits the seller's risk of producing poor-quality materials. D. All of the above are true.
b
The application of statistical techniques to determine whether a quantity of material should be accepted or rejected based on the inspection or test of a sample is known as A. specification review. B. benchmarking. C. acceptance sampling. D. the Deming Wheel.
c
What is the statement used to describe the proportion of defective items (outside of specifications) that the buyer will accept in a shipment? A. acceptance sample ratio B. batch acceptance rate C. acceptable quality level D. value standard
c
Which of the Baldrige criteria is given the most weight in selecting winners? A. customer focus B. leadership C. results D. workforce focus
c
Which of the following is true about ISO 9001:2008, the standards governing documentation of a quality program? A. Compliance with ISO 9001:2008 standards indicates to customers that companies can provide documentation to support whatever claims they make about quality. B. Companies become certified by proving to a qualified external examiner that they comply with all the requirements. C. Compliance with ISO 9001:2008 standards says nothing about the actual quality of a product. D. All of the above are true.
d
Attribute Control Charts
p-chart c-chart
The sample mean is
the sum of the observations divided by the total number of observations.
