Lean Six Sigma

Six Sigma project characteristics

-Clearly connected to business priorities -strategic and annual operating plans -Project typically of major importance to co. -represents a major process improvement/financial improvement -Reasonable scope(3-6 months) -quantitative measure of success -Baseline and goals clearly defined -Importance is clear to organization -Support and approval of management

What is a scatter diagram?

-Graph of one sample variable versus another -may show cause and effect relationship(may show strong correlation) Correlation: +1 means perfect positive relationship -1 means perfect negative relationship 0 means no significant relationship -Extrapolate with care- dont go beyond the limits of the observed data -stratify or sort by classification -beware of happenstance or hidden variable data in which there may appear to be a strong correlation but no valid reason for it -correlation does not imply causation(the action of causing something)

Six Sigma project structure

-Major projects led by black belts -Project teams include stakeholders including financing -Each project has a champion -subject matter experts may be necessary to assist with analysis -problem statement -quantifiable and measurable objectives Achievable Supportive of business requirements -Addresses critical customer needs -Tangible or financial payback

Difference between DFSS and DMAIC

-Project about 4-6 months -Extensive definition of customer requirements(CTQ's) -Heavy emphasis on bench marking and simulation; less on baselining

Who is Dr. W Edwards Deming? What is he known for?

-Proposed the Theory of profound knowledge-which he stated was essential for any organization that desired to be competitive in today's marketplace -did much of research in Japan -Proponent of SQC -Helped turn around the quality issue in japan production

What are some characteristics of stable processes?

-Stable processes only occur when normal variation in a process (said to be stable) -stable processes are predictable -Stable processes are in (statistical) control -Stable processes have a known process capability

Cause-Effect diagram(Ishikawa diagram)

-Tool used to organize team's knowledge about a process(organized brainstorming: we want lots of ideas, and out of the box thinking) -graphic picture of what is known about the process -communication tool -Assist in reaching a common understanding of the problem and exposes the potential drivers of the problem -Named after Dr. Ishikawa Typical categories for branches: 1) Manufacturing: -methods -materials -equipment -people -environment 2) Service: -procedures -processes -Policies -People

Explain implementing six sigma

-Top management support and participation is essential(Top down approach) -Project identification -Resource allocation -Data based decision making -Measurement and feedback

What is the CQI process?

"Continuous quality improvement" process CQI (Continuous Quality Improvement) is an approach to quality management that builds upon traditional quality assurance methods by building and strengthening the company's organization and systems and focusing on "process" rather than the individual.

What does Felix qui potuit rerum cognoscere causas from Victor Hugo mean?

"Happy is the person who understands the causes of things"

What is QMS?

"Quality management system" -Everything we do can be improved

For a normal curve, we expect to find what percent of values between +- 1 standard deviation form the mean? For +-2 standard deviations? For +-3 standard deviations?

1 sigma-68% 2 sigma-95.5% 3 sigma-99.73%*

Explain Knowledge of systems. Whose responsibility are systems? what is their goal regarding systems?

1) A system is a network of interdependent components that work together to try to accomplish an aim 2) Systems are managements responsibility 3) Management tries to optimize the entire system over time

How long are Lean six sigma certificates valid for?

3 years. But no retest required....$15 fee

What 2 things must be performed before calculating process capability?

A histogram A control chart

What is the 3rd step(A) in DMAIIC?

Analyze: -Make sense out of the data that was measured -Shows the amount of improvement that might be possible to make the critical quality characteristic "best in class"

Explain standardized work.

Create a flow to improve tack time or cycle time

What is the major structured approach of Six sigma?

DMAIIC

What is the 5th(I) step of DMAIIC?

Improvements should be implemented in a logical and planned fashion A project plan is developed and managed

What does DPMO stand for?

defects per million opportunities Add both tails together and multiply by 1 million

In order to effectively monitor any process effectively, what pieces of information must be known?

1) Central location ( average or mean) 2) Spread(Variation given by standard deviation) 3) Shape(tells how data looks in a histogram..bell = nominal) 4) Relationship of variation to time(is it constant or changing over time?...usually changing)

What are 3 components of process capability?

1) Design specifications 2) Centering of natural variation 3) Range or spread of variation

What is 8 step problem solving?

1) Form a team 2) Define a problem 3) Contain problem 4) Analyze the root cause 5) Select solution 6) Implement 7) Prevent re-occurrence 8) Celebrate Used by aerospace industry

What are 4 out of control checks?

1) Is the shape of the histogram what we expected? 2)Are all of the sample averages between the control limits for averages? 3) Are all the sample ranges between the control limits for ranges? 4) Is the pattern of variation as time goes by random?(See Western electric rules)

What does knowledge of systems refer to? knowledge of statistics? knowledge of psychology? knowledge of knowledge?

1) Knowledge of processes 2) Knowledge of variation and how to interpret it 3) Knowledge of the connection between psychology and motivation 4) Creating a framework based on previous knowledge

What three things are necessary for Six Sigma to be effective?

1) There must be a process in place 2) The process must be brought into control statistically(meaning we know how it works) 3) The process must be improved(by reducing variation)

How do you determine the number of bins for a histogram? The with of each bar?

1) We find the number of bins using the formula K = sqrt(# of observations) 2) width = R/K or the range of the entire data set divided by the number of boxes

What does +-3 standard deviations from the mean have to do with causes of variation?

3 sigma represents the expected limits of common cause variation necessary for a stable and predictable process

What is a Histogram? What does it mean when we dont get the shape we are expecting?

A Histogram- is a graphical representation of data in a bar chart format. They are used to observe the "Shape" of the data. When we dont get he shape we expect(bell), it is an indication of a special cause of variation

What is a flowchart?

A graphical representation of a process This is the first step in many process improvement projects To make one, make a map of the process showing elements such as: -Operations -Decisions -Delays -Storage's -handling Process analysis using a flowchart: -ask: ---Why, when, where, who, how, why

FMEA definition

A procedure by which each potential failure mode in a system is analyzed to determine the result of effects thereof on the system and to classify each potential failure mode according to its severity, the likelihood of it occurring, and the ability of the system to prevent it from occurring -most wisely used analysis procedure in practice at the initial stages of system development -usually performed during the conceptual and initial design phases of the system in order to assure that all possible failure modes have been considered and that proper provisions have been made to eliminate all the potential failure Created by Aerospace industry("Big three") See FMEA flow chart and sample form 188,189 Stands for "Failure modes and effect analysis"

Process definition

A process is a set of conditions or a set of causes which work together to produce a given result Includes: Inputs, outputs, transformations, and feedback A process must meet 4 requirements: 1) It is recurrent(repeatedly occurring) 2) it affects some aspect of organizational capability 3) It can be accomplished differently so as to make a contribution to customer or/and profit 4) It involves coordination

Explain control

A process is said to be in statistical control when, through the use of past experience, we can predict how the process will vary in the future *Statistical process control = Predictability*!!

What are control charts? Which components represent the "Voice of the process"? Which components represent the "Voice of the customer"?

A statistical tool which shows the amount and type of variation present in any process that is being monitored Tells us if the process is stable, predictable, or in control. Which components represent the "voice of the process"?: UCL-upper control limit LCL-lower control limit CL-center line(shows where the characteristic average falls) Which components represent the "voice of the customer"?: USL- upper specification limit or upper customer requirement LSL- lower specification limit or lower customer requirement Nom- Nominal-the target we aim at to give the customer exactly what they want(kind of like the customer average)

What is Root cause analysis?

All organizations have problems that plague their operations...we called many of these special causes of variation Root cause analysis is the process of finding and eliminating the cause, which would prevent the problem from returning( rather than the quick fix). Only when the root cause is identified and eliminated, can the problem be solved.

Who is considered a customer?

Anyone whose success or satisfaction depends on ones actions -Gather voice of customer -Analyze customers needs

What is the sole use of statistics in Six Sigma?

As tools for interpreting and clarifying data

What is quick changeover in Lean?

Basically how fast some process can be achieved... Think racecar pit crew....they have a very quick changeover

Knowledge of knowledge

Basically that rational prediction comes from a good understanding of theory and knowledge built through systematic revision and comparison of theory based on comparison of prediction with observation

What does Six Sigma require besides statistics?

Changes in the culture of the organization!! This requires a deep commitment from the highest levels of management This also requires a tolerance for endlessly questioning the validity of sacred company beliefs and the way things "are done around here" *Companies who aren't willing to change their culture will be unsuccessful with this system. Six Sigma purposely changes the existing rules and regulations in order to make them better

Explain what it means to interpret charts and what out of control means

Charts monitor processes and provide a record of behavior over time Out of control means: -Not stable -special cause variation is present -Stop and identify the special cause

What is a check sheet?

Check sheets are used to record data They are: visual, easy to interpret, organize data collection Structured formats for process data that show underlying patterns used in forming histograms/pareto charts Record the frequency of occurrence of a certain product or service characteristic can be either tabular or schematic Ex: 174,175, 176

What is the difference between special and common causes of variation?

Common causes - refer to situations, usually within those systems and processes that are more ongoing, chronic, and persistent. -These will always exist Special causes- Refer to sentinel events, one-time circumstances, or other unique out-of-the-ordinary circumstances We must act according to the type of cause and avoid tampering( especially when using statistical control-we must know the type)

What is a Six sigma master black belt?

Competent teachers, and must show proof that they saved a required amount of money using Six sigma Must have trained people... Should be competent in : Training, coaching, mentoring, facilitating, statistics, and projects

What are control limits? What are they set by?

Control limits describe the representative nature of a stable process. They identify the expected limits of normal, random, or chance variation that is present in the process being monitored Control limits are set by the process!! "Voice of the process"

What is the 6th(C) step of DMAIIC?

Control(Standardize and validate): Measures have been implemented and steps are taken to make sure improvements are maintained

What does six sigma quality require regarding standard deviations?

Customer requirements are 6 standard deviations from the mean in either direction. Lower customer requirement = -6 sigma Upper customer requirement = +6 sigma

What does the Six Sigma structured approach refer to?

DMAIIC *Be able to know and recreate the chart

What is variation equivalent to?

Defects

What does DMAIIC stand for? Who added the second I?

Define Measure Analyse Improve Implementation Control IIE added the second I

What does the D in DMAIIC stand for?

Define: This includes identifying the problem and setting the scope Also: Identifying customers and what is important to them Determining what is critical to quality(What parts of the process are causing defects) Determining how to measure Determining what we want to accomplish Business case->Project charter(describes project...Set milestones!)-->Initial process mapping--->Voice of customer

What does DFSS mean and refer to?

Design for Six Sigma and it refers to DMADV or Define, Measure, Analyze, Design, and verify Used to design new and replace old processes Redesigning product or service to achieve six sigma business level (customer driven design of processes with 6 sigma capability) Predicting design quality up front CTQ flowdown Utilizes process capabilities to make final design decision Monitor process variances to verify 6 sigma customer requirements are met. A phased methodology- includes both the design tools and innovative tools for designing products and processes that generate customer value--> The phases are DMADV..

Who is considered the "Father of SQC"?

Dr. S Shewhart

What are the "6 thinking hats"?

Emotional response Constructive criticism Logical facts Optimistic outlook Creative opinion The proper choice

Explain Dr. Demmings school bus

Explain the "voice of the process(VOP)" and the "voice of the customer(VOC)" What happens if the VOP is within the VOC? what if it isnt withing the VOC? What is nominal/special causes of variation in this example?

(T/F) not everything varies.

FALSE!! Everything varies. Nothing is exactly 100% repeatable

How do you calculate Cpk?

For one sided: Cpku = abs(Uspec-Mean)/(3sigma) CpkL = abs(mean-Lspec)/(3sigma) Cpk is also equal to the sigma level divide by 3

Explain psychology and the theory of motivation

Generally people want to do a good job and contribute The key here is to tap into the intrinsic motivation- which is basically finding what specifically motivates people. Must drive out fear and build trust A good team has tapped into intrinsic motivation

What is the basic theorem of Variation?

If you always do what yo have always done, you will always get what you always got "Corollary to the basic theorem of variation" Insanity is doing the same thing over and over and expecting different results

What is the 4th(I) step of DMAIIC?

Improvement: -improvements evaluated in a logical and planned fashion -Tools used: Design of experiment Simulation Cost justification Project management Correlation Regression Balance the scope, cost, and schedule. (These are in order of most to least important) unless youre running the project, then schedule is the most important

Explain data based decision making

In successful 6 sigma organizations, both strategic and operational decisions are guided by facts and data You must make use of the information you obtain

What is a six sigma Green belt?

Introductory participant in the process Understand problem solving, data collection, data interpretation, variation, process capability, and cost analysis

What is the Kano model?

It defines three types of quality requirements: 1) One-dimensional-Satisfaction when fulfilled, dissatisfaction when not fulfilled 2) Expected(taken for granted when fulfilled but result in dissatisfaction when not fulfilled) 3) Exciting-Satisfaction when fully achieved, but do not cause dissatisfaction when not achieved -Apple is known for using Exciting

What is Six sigma? What is a goal of Six Sigma?

It is a customer focused, well defined problem solving methodology supported by a handful of powerful analytic tools The goal of six sigma is to take small steps and no backwards steps

What is the definition of six sigma?

It is a customer focused, well defined problem solving methodology supported by a handful of powerful analytical tools Continuous improvement is driven by the execution of carefully selected projects Small steps and none backwards "Youre a change agent"

Who is accredited with using Six Sigma most successfully?

Jack Welch-CEO of GE

What distinguishes Six Sigma from other quality improvement methods?

Justifying improvement in the language of management

What are champions in six sigma?

Key management personnel who provides support, resources, and encouragement for the process More in depth knowledge of measurement needed, especially measurement and interpretation of the process measurements

What is total productive maintenance in Lean?

Making sure machinery always works

What three things are used to describe the central location?

Mean Median Mode Xbar = sample average Mu = population average The average is the expected value or the balance point

What is the second step(M) in DMAIIC

Measure: -Identify and verify critical quality characteristics -Estimate current capability Determine where you are relative to desired objectives Measure using Process capability, measurement system analysis, and Cost of quality(Appraisal, detection, and failure) Steps: 1)Identify the metrics 2) Prioritize metrics 3) Data collection plan Validate measurement system 4) Measure the process(Id process capability and display data)

Explain a target in statistics

Most measures have a target In manufacturing it is called the nominal In service, it may be called the customer requirement Example, a promise to deliver something with in 24 hours

Who coined the term "Six Sigma"? Why?

Motorola Because they created a system that sought to achieve 3.4 defects per ppm of units or oppotunity

What is Muda?

Muda is Japanese for Waste!! -anything that is wasteful and doesn't add value -waste reduction is an effective way to increase profitability -Process adds value by producing goods or providing a service -Waste is when more resources are consumed than necessary to produce the goods or provide a service

Data collection is normally what?

Nominal

Which has the highest priority for an improvement project?: More than capable Capable Not capable

Not capable!-because it isnt cutting it for us

Explain Six Sigma and the 1.5 sigma shift

Originally, Six sigma reduces effects to 2 PPB, however, Motorola determined that over time this number deteriorates by a 1.5 sigma shift....Which reduces the rate to 3.4 deffects PPM

How do we measure process capability?

PC is measured by the proportion of output that can be produced with in design specifications A measure of the uniformity of a process It can be measured only if all the special cases have been eliminated and the process is in statistical control

What is Pareto analysis? The Pareto principle?

Pareto analysis: -reflects the frequency or impact of problems. -can be table or bar chart -guide to selecting opportunities and prioritizing Pareto principle: -Derived from the 80-20 principle: 80% of the problems are due to 20% of the causes -identifies problems and most probable causes in a study -Points out significant frequencies or costs

What are green belts required to know?

Percent or proportion Non-Conforming Cp index Cpk Index

What is process monitoring?

Process monitoring is performed to determine the type and amount of variation that is present in a process as time goes by 2 types variation: -Common cause -Special cause

What 2 things are used to explain the variability?

Range(R) Standard deviation-mathematical measure of the variability of the data about the mean...S for sample, and sigma for population Sx = sqrt( sum(i=1 to n) of (Xi-Xbar)^2/(n-1)) where n = the number of values in the sample

Reducing variation does what?

Reduces cost

What is percent non-conforming?

Reflects the proportion of the population that we normally expect NOT to meet the process specifications Corresponds to the "tail" areas on a normal curve

Compare short term and long term capability measures

Short term shows the capability at a specific instance in time Long term shows how the expected capability of the process based on statistical projections using inherent process variability

What are the 5s's in Lean?

Sort Set in place Shine Standardize Set in place

How to address special and common causes of variation

Special cause: -Find the special causes and address -Those closest to the process are most likely to find the special cause of variation Common causes: -Take action on the system -Management is responsible for the system

What are Specification limits

Specification limits are those limits which describe the characteristics the product or process must have in order to conform to customer requirements or to perform properly in the next operation. "Voice of the customer"

What is SQC? Who was a strong proponent ?

Statistical quality control -Dr.Deming was a strong proponent

Six Sigma should be viewed as a ________, not a ________.

Strategy, not destination

What is ISO 9000?

Strong and definite operating procedures: -Everything is documented -Lots of audits

Explain the Western electric Rules... What do they mean?

The are used to interpret a chart and these specific rules tell when a process is out of control 1) Single point out of limits 2) Adjustment? 3) Reduction in variability 4) 2 or 3 consecutive points near one control limit 5)Run(7+ consecutive points on either side of center-line or 7+ increasing or decreasing points) 6) Cycle(repetitive pattern) 7) Trends Generally patterns = out of control and random is in control

What is the average range?

The average range is the estimate for total process variability. The average range is the average of the sampling ranges Symbol = Rbar

What is the grand average?

The grand average is the process average -It is usually calculated as the average of the sample averages(as long as the samples are the same size) -Also the average of all of the individuals Symbol = Xdblbar

What is a process owner?

The individual who has the ultimate authority to change a process Should be identified for every project!! Works with Six sigma team, and runs operations after adjustments have been made and implemented

Process capability

The measured reproducibility of the product turned out by the process. It defines the limits we would normally expect virtually all individuals to fall with in A process is "Capable" when it is operating at a 3 sigma level Also "Capable" when VOP is with in VOC? Is also the range over which the natural variation of a process occurs as determined by the system of common causes It is the ability of the combination of people, machines, methods, materials, and measurements to produce a product or service that will consistently meet the design specs.

How do you calculate Cp?

The process must be centered!!! Cp = (Uspec-Lspec)/ 6sigma

What is Lean(Toyota production system(TPS))

The purpose is to reduce waste!! -Identify customers value(what they find valuable) -Draft value stream map -Improve stream : remove waste Balance workload Flow the process and pull the service/product -Effects: improved delivery time reduced waste less Cost$$ ..Some say Lean is a process philosopy with three purposes: "To eliminate wasted time, effort, and material" "To provide customers with make-to-order product" "To reduce cost while improving quality"

Explain customer supplier relations and Six Sigma

The purpose of all Six Sigma work is to better serve customer needs and expectations thereby providing increasing value to the customers and ensuring repeat business.

What are the 7 waste + 1 in Muda?

The seven Waste: 1) Overproduction(#1 waste) 2) Inventory(sitting = waste) 3) Defects(repair, rejects, rework, corrections) 4) Motion 5) Processing(overprocessing) 6) waiting 7) Transportation(material movement) +1: Skill abuse- not using teamwork and individuals strengths effectively

What is the sigma level?

The sigma level is a measure of how many standard deviation variation measurement units fit between the mean and the spec limit This is the smaller of the 2 z-values if they are unequal.

What are capability indexes? What is Cp? What is Cpk?

They show the relationship between the process capability and the process specifications Cp- measures potential capability assuming that the process average is equal ti the middlepoint of the spec limits and the process is operating in statistical control (it is a guide for determining whether better aim or variation reduction will have the biggest impact on the improvement effort) Cpk- reflects the current process mean's proximity to either specification limit. When the process is centered, Cp=Cpk When it is not centered use Cpk Cp or Cpk less than 1 = "Not capable" Cp or Cpk = 1 = "Capable" Cp or Cpk > 1 = "More than capable"

What is a six sigma steering committee?

They: -identify projects -identifies black belts -allocates resources -Monitors progress -Reviews effectiveness -Establish implementation strategy and policies

What is a six sigma black belt?

Thoroughly trained individuals expert in all the analysis tools Structured around project where analysis tools are applied as part of training Expected to: Teach Coach Transfer knowledge Identify opportunities Influence the organizational use of Six Sigma methods

When do you use the mean? When do you not?

Use the arithmetic mean if the shape of the distribution is symmetrical Use the median or the mode if the shape of the distribution is not symmetrical

Control limits(Variables vs. Attributes)

Variables: -Averages, ranges, medians, std deviations, ect. -expected to construct and interpret this control chart -Individual and moving ranges Attributes( characteristic caused by something): -Percent defective -Number defective -Number of defects -Defects per unit Ex: Percent defective caused by variability

What is Variation the "voice" of? How should we use statistics and variation?

Variation is the voice of the system or process We can use statistics to make the invisible visible-showing us patterns and types of variation.

Why do we describe data in six sigma? What 4 things do we need to know to do this?

We describe data in six sigma to assist with the analysis. In order to completely describe the data, we need to know the following: 1)Location 2) Spread 3) Shape 4) Variation over time

What does it mean when the shape is not normal? What do we do?

When the shape is not normal, we must compare our shape with the expected shape to see if the process is behaving like it always has... If the pattern is different than what we would expect, we may not be doing what we always have, we may not be predictable, we may not be stable