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Six Sigma

Subjects : certifications, six-sigma, business-skills

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What is Type 1 Error?
Concluding there has been an effect/change when there has not.
Different types of defects are listed (used for Pareto chart)
To obtain a certain desirable outcome from the process
= yij - y(bar)i --> value minus sum of that treatment (of row)

2. What is the 5S model?
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
The ability of a process to consistently meet customer specifications.
Is the consequence of the failure.

3. Definition of Interaction
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
An assertion or conjecture concerning one or more populations
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.

4. List two appraisal costs.
It usually isn't possible to hold all other variables constant - There is no way to account for the effect of joint variation of independent variables - such as interaction - There is no way to account for experimental error - including measurement v
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
Sampling for SPC is done real time.
Hold all input variables constant except one. Observe the response as you vary the single input.

5. What is the formula for standard deviation?
If the Response vs. Levels graph if the response lines are not parallel (crossing)
Can't tell without a Range chart.
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
=sqrt(Σ(x-x-bar)^2)/(n-1))

6. Histogram by Hand
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan
Fishbone - cause-and-effect diagram.
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
1) Identify the Range (Max Value - Min Value) 2) Determine # of bins 3) Determine the Width of each bin --> (Range / # Bins) 4) Put values in correct Bin

7. Non-random patterns (Run Charts)
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.
Supplier - input - process - output - customer.
Rapid improvement process.
Shifts - Trends - Repeating patterns - Correlation with known events

8. List two components of external failure.
Taguchi
Variable.
Complaint adjustment - returned material - warranty charges - allowances - loss of future business.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables

9. Does it ever make sense to accept a job when a process is incapable?
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
Linearity - normality - homoscedasticity - independence.
Shifts - Trends - Repeating patterns - Correlation with known events
No -- if it is not the same - it can only be worse!

10. Where should specifications fall in relation to ± 3 sigma for the process in order for a process to be capable.
Complaint adjustment - returned material - warranty charges - allowances - loss of future business.
10 for Hazardous without warning 1 for none
Inventory = throughput x flow time.
Outside.

11. Who developed the fishbone diagram?
10 if Almost impossible to detect
Kaoru Ishikawa.
Assigns scores to weighted criteria for each project under consideration.
Through producer/consumer negotiation.

12. Residual(eij)
Fractional factorial designs (orthogonal arrays)
Define - measure - analyze - design - verify.
Initiated before or at design concept finalization
= yij - y(bar)i --> value minus sum of that treatment (of row)

13. Explain the difference between technical and functional service quality.
Different types of defects are listed (used for Pareto chart)
A tool that shows the physical flows through a space.
Plot the residuals vs. the fitted values (mean of each group - y(hat) = y (bar)i ) - Assumption of ____________not rejected if the dispersion of every group is approximately the same.
Technical quality is the "what" of the service; functional quality is the "how."

14. Regression Analysis
Workers - machines - materials.
Concluding there has not been an effect/change when there has.
Kaoru Ishikawa.
Technique used to relate through a model - one or more independent variables and a dependent variable (response)

15. Design of Experiments (DOE) approach
Not necessarily.
If the Response vs. Levels graph if the response lines are not parallel (crossing)
Prevention and appraisal costs are balanced against internal and external failure.
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions

16. Define benchmarking.
Failure Modes and Effects Analysis
Studying firms with the best performance in a particular area.
Large enough to find two of the attribute - on average.
100%

17. Process check sheets
=sqrt((p*(1-p)/n)
Is what induces the failure
Used to create frequency distribution tally sheets
It usually isn't possible to hold all other variables constant - There is no way to account for the effect of joint variation of independent variables - such as interaction - There is no way to account for experimental error - including measurement v

18. Process occurance ranking
99.73%
Can't tell without a Range chart.
Taguchi
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces

19. Define yield.
Observed variation in response is caused by the input
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
The ratio of outputs to inputs; 1-scrap.
Mean time to failure.

20. FMEA
Fitness for use.
Is the consequence of the failure.
Failure Modes and Effects Analysis
A systemized group of activities designed to 1. recognize and evaluate the potential failure of product/process and its effects 2. Identify actions which could eliminate or reduce the chance of potential failure ocurring 3. document the process

21. Creating a Run Chart
1.Interactions can be detected and measured 2.Each value does the work of several values 3.Experimental error is quantified and used to determine the confidence the experimenter has in the conclusions
Consumer risk.
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
The cycle time required to meet demand.

22. For what is a p-chart used?
Through producer/consumer negotiation.
consists of plotting the residuals vs. the order of each experiment - If - as in the case of the constant variance a random horizontal band is obtained - the ______________ of the residuals is not rejected. (should be random above a below the line i
To monitor a process when measurement by attribute is used.
p-bar - the long-run percent defective.

23. What does a project prioritization matrix do?
Assigns scores to weighted criteria for each project under consideration.
Shows the temporal flow of activities in a project network.
To be a member of a Six Sigma project team.
Concluding there has been an effect/change when there has not.

24. What is a Gantt chart?
Fewer good units to sell - increased variable cost/unit.
Before production starts
Blame.
Shows the temporal flow of activities in a project network.

25. There are two milling machines in the shop. Data has been collected on one to compute control limits for both. This is acceptable SPC practice - true or false and why?
False - because each machine will have different natural tolerances.
It looks to minimize the probability of a failure - or to minimize its effects
95%
=sqrt(Σ(x-x-bar)^2)/(n-1))

26. What does the abbreviation UCL stand for?
Conformance to specifications.
Upper control limit.
Not necessarily.
Walter A. Shewhart

27. Risk Priority Number RPN
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
Supplier - input - process - output - customer.
To manage the Six Sigma project.
Pleasing to the senses.

28. What is poka yoke?
Mistake-proofing.
Is the consequence of the failure.
To monitor a process when measurement by attribute is used.
Stratify a particular defect type according to logical criteria

29. What type of risk is associated with Type II Error?
QFD
Actual drawings - layouts - maps - etc which show where a defect occurs
Consumer risk.
Define - measure - analyze - improve - control.

30. In a Z table - what is Z?
The number of standard deviations some value is from the mean.
The gap between specifications and how service is performed.
Blame.
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"

31. What does SIPOC stand for?
Supplier - input - process - output - customer.
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan
0.9^3 or 72.9%
Lean (or JIT).

32. With Six Sigma capability - how many defects per million opportunities would you see?
3.4 (assuming 1.5 sigma shift in the mean)
The Japanese national quality award.
Shows the temporal flow of activities in a project network.
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.

33. What is FMEA?
Failure Modes and Effects Analysis
To do a capability study for a non-centered process.
Walter A. Shewhart
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions

34. What is Value Stream Mapping?
Mean time to failure.
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
The gap between what customers expect and the service they receive.
A tool that shows where there is waste in a process.

35. What is an affinity diagram?
Prevention and appraisal costs are balanced against internal and external failure.
A brainstorming tool that shows the connections between ideas.
Variable.
Walter A. Shewhart

36. Define features.
The secondary characteristics of a product; "bells and whistles."
Lean is waste reduction - Six Sigma is variation reduction.
= yij - y(bar)i --> value minus sum of that treatment (of row)
It looks to minimize the probability of a failure - or to minimize its effects

37. What type of risk is associated with Type 1 Error?
It's good -- but it's still out of control!
Producer risk.
Define - measure - analyze - design - verify.
False - because each machine will have different natural tolerances.

38. What is the difference between Lean and Six Sigma?
Look for the assignable cause of non-random variation.
Kaoru Ishikawa.
Lean is waste reduction - Six Sigma is variation reduction.
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper

39. If a three-stage process has 90% yields at each stage - what is the overall yield?
Concluding there has been an effect/change when there has not.
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.
0.9^3 or 72.9%
An interaction is defined as a dependence relationship between the response and the levels of two or more variables

40. Complete this quality phrase: 'Fix the process - not the _____.'
The manager in charge of a process being improved in a Six Sigma project.
p-bar - the long-run percent defective.
A tool that shows the physical flows through a space.
Blame.

41. Who is a process owner?
The manager in charge of a process being improved in a Six Sigma project.
The gap between what is promised and what is delivered.
Fewer good units to sell - increased variable cost/unit.
Actual drawings - layouts - maps - etc which show where a defect occurs

42. In the Service Quality Gap Model - what is Gap 2?
=sqrt((p*(1-p)/n)
The gap between what management thinks customers want and the process specifications.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
Stratify a particular defect type according to logical criteria

43. F value
The ratio of outputs to inputs; 1-scrap.
Not necessarily.
F_alpha - df(tr) - df (error)
Studying firms with the best performance in a particular area.

44. What is the role of a green belt?
To be a member of a Six Sigma project team.
No -- only if the process is also capable.
Workers - machines - materials.
Kaoru Ishikawa.

45. What is the formula for the standard deviation of a proportion?
Technical quality is the "what" of the service; functional quality is the "how."
A tool that shows performance along key dimensions all at once.
=sqrt((p*(1-p)/n)
It's good -- but it's still out of control!

46. Affinity Diagrams
Producer risk.
Organize ideas into meaningful categories by recognizing their underlying similarity
Can't tell without a Range chart.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables

47. What are the four perspectives of the Balanced Scorecard?
The US national quality award.
100%
The number of standard deviations some value is from the mean.
Financial - customer - internal process - innovation and learning.

48. Approximately what percent of a normal distribution falls between ± 1 standard deviations from the mean?
The number of standard deviations some value is from the mean.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
68%
Conformance to specifications.

49. In a regression - what does the coefficient of the intercept tell you
What the value of the dependent variable is when the independent variable is zero.
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
=sqrt(Σ(x-x-bar)^2)/(n-1))
Studying firms with the best performance in a particular area.

50. What is a Gage R&R?
Prevention and appraisal costs are balanced against internal and external failure.
p-bar - the long-run percent defective.
Is the consequence of the failure.
A tools that is used to measure the amount of variation in the measurement system arising from the measurement device (repeatability) and the people taking the measurement (reproducibility).