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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. For what is an x-bar chart used?
Fewer good units to sell - increased variable cost/unit.
Failure Modes and Effects Analysis
To monitor a process when measurement by variables is used.
Different types of defects are listed (used for Pareto chart)

2. Define product reliability.
How likely it is to have an F statistic of that value if there really is no relationship between the dependent variable and the independent variable(s).
Mean time to failure.
Prevention - appraisal - internal failure - external failure.
The number of standard deviations some value is from the mean.

3. How are LQL and AQL determined in an acceptance sampling plan?
The number of standard deviations some value is from the mean.
Through producer/consumer negotiation.
Stratify a particular defect type according to logical criteria
Define - measure - analyze - improve - control.

4. Complete this quality phrase: 'Fix the process - not the _____.'
X-bar-bar
Blame.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
Kaoru Ishikawa.

5. One factor at a time (OFAT)
Inventory = throughput x flow time.
Complaint adjustment - returned material - warranty charges - allowances - loss of future business.
Attribute.
Hold all input variables constant except one. Observe the response as you vary the single input.

6. FMEA
Attribute
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
Prevention and appraisal costs are balanced against internal and external failure.
5%

7. Affinity Diagrams
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
The ratio of outputs to inputs; 1-scrap.
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
Upper control limit.

8. What does SIPOC stand for?
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.
Is what induces the failure
Supplier - input - process - output - customer.
A descending order-sorted bar chart with a cumulative percentage line.

9. What is FMEA?
Failure Modes and Effects Analysis
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
Concluding there has been an effect/change when there has not.
Inventory = throughput x flow time.

10. What is the formula for standard deviation?
Prevention and appraisal costs are balanced against internal and external failure.
The manager in charge of a process being improved in a Six Sigma project.
=sqrt(Σ(x-x-bar)^2)/(n-1))
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).

11. List two components of internal failure.
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
5%
3.4 (assuming 1.5 sigma shift in the mean)
Scrap - rework - retest - downtime - yield losses - disposition costs.

12. DOE
The gap between what customers expect and the service they receive.
Supplier - input - process - output - customer.
= yij - y(bar)i --> value minus sum of that treatment (of row)
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan

13. Process occurance ranking
Workers - machines - materials.
To manage the Six Sigma project.
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
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.

14. List two components of external failure.
Upper control limit.
Sort - Set in Order - Shine - Standardize - Sustain
To be a member of a Six Sigma project team.
Complaint adjustment - returned material - warranty charges - allowances - loss of future business.

15. What is Type 1 Error?
Variable.
Look for the assignable cause of non-random variation.
To do a capability study for a non-centered process.
Concluding there has been an effect/change when there has not.

16. What does DMAIC stand for?
=sqrt(Σ(x-x-bar)^2)/(n-1))
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
The House of Quality.
Define - measure - analyze - improve - control.

17. Define performance quality.
No -- only if the process is also capable.
The primary operating characteristics of a product.
Look for the assignable cause of non-random variation.
Concluding there has been an effect/change when there has not.

18. F value
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
A tool that shows performance along key dimensions all at once.
Mistake-proofing.
F_alpha - df(tr) - df (error)

19. Which quality guru developed the concept of loss to society?
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
99.73%
Taguchi

20. What is the difference between Lean and Six Sigma?
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
Lean is waste reduction - Six Sigma is variation reduction.
Complaint adjustment - returned material - warranty charges - allowances - loss of future business.
=sqrt((p*(1-p)/n)

21. Residual
Fewer good units to sell - increased variable cost/unit.
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
The gap between what management thinks customers want and what customers really want.
X-bar-bar

22. What inventory approach contributes to process quality by "lowering the river to find the rocks?"
Speed - courtesy - competence - and ease of repair.
Lean (or JIT).
The degree to which a product meets pre-established standards.
Fishbone - cause-and-effect diagram.

23. Why do you need two control charts for variables SPC?
The target number of standard deviations from the mean for specifications.
Because the mean and standard deviation are independent of each other.
The primary operating characteristics of a product.
Walter A. Shewhart

24. What is DMADV?
Not necessarily.
Define - measure - analyze - design - verify.
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
A descending order-sorted bar chart with a cumulative percentage line.

25. Creating a Run Chart
Scrap - rework - retest - downtime - yield losses - disposition costs.
They move closer to the center line.
Initiated before or at design concept finalization
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median

26. In the Service Quality Gap Model - what is Gap 2?
The gap between what management thinks customers want and the process specifications.
Variable.
Stratify a particular defect type according to logical criteria
Central Limit Theorem

27. In your major - courses are pass-fail. Would you monitor performance using attribute or variable SPC?
Attribute
Fitness for use.
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
Kaoru Ishikawa.

28. Does it ever make sense to accept a job when a process is incapable?
Look for the assignable cause of non-random variation.
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
Speed - courtesy - competence - and ease of repair.
Technical quality is the "what" of the service; functional quality is the "how."

29. In the Service Quality Gap Model - what is Gap 5?
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.
Consumer risk.
False - because each machine will have different natural tolerances.
The gap between what customers expect and the service they receive.

30. If a Cp shows that a process is not capable - should you calculate Cpk?
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
Method developed by Ishikawa to graphically display the causes of any given problem
No -- if it is not the same - it can only be worse!

31. What are the 5 Ss?
To do a capability study for a non-centered process.
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
Is what induces the failure
Sort - Set in Order - Shine - Standardize - Sustain

32. What is the Deming Prize?
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
The Japanese national quality award.
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
3.4 (assuming 1.5 sigma shift in the mean)

33. What are the three main categories of assignable cause?
Prevention - appraisal - internal failure - external failure.
Workers - machines - materials.
p-bar - the long-run percent defective.
No -- only if the process is also capable.

34. Test for constant variance
To obtain a certain desirable outcome from the process
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.
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
Actual drawings - layouts - maps - etc which show where a defect occurs

35. Explain the difference between technical and functional service quality.
= y = Beta(0) + Beta(1)X + epsilon y=dependent variable (response) x=independent variable (predictor of y) - epsilon=error component - Beta(not)=intersection. If data include zero - it represents the mean of the distribution of y when - x=0. It does
Technical quality is the "what" of the service; functional quality is the "how."
Mean time to failure.
p-bar - the long-run percent defective.

36. In the Service Quality Gap Model - what is Gap 1?
Kaoru Ishikawa.
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.
Inventory = throughput x flow time.
The gap between what management thinks customers want and what customers really want.

37. In the Service Quality Gap Model - what is Gap 3?
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
Defects Per Million Opportunities
The gap between specifications and how service is performed.
Concluding there has not been an effect/change when there has.

38. When yields decrease - what are the two effects on contribution?
To obtain a certain desirable outcome from the process
p-bar - the long-run percent defective.
To be a member of a Six Sigma project team.
Fewer good units to sell - increased variable cost/unit.

39. In a regression - what does R-square tell you?
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Waste.
10 for Hazardous without warning 1 for none

40. What is an affinity diagram?
Assigns scores to weighted criteria for each project under consideration.
A brainstorming tool that shows the connections between ideas.
=sqrt((p*(1-p)/n)
Consumer risk.

41. For what is a p-chart used?
An assertion or conjecture concerning one or more populations
To monitor a process when measurement by attribute is used.
Defects Per Million Opportunities
The ratio of outputs to inputs; 1-scrap.

42. What is muda
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
To mentor/coach (and sometimes train) black belts.
Waste.
No -- if it is not the same - it can only be worse!

43. How does Juran define quality?
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
Waste.
Fitness for use.
Because the mean and standard deviation are independent of each other.

44. Daniel Test
Another way to assess the significance of the analyzed factors is through a graphic procedure developed by C. Daniel when only one replicate (a single observation) was obtained:
To do a capability study for a non-centered process.
=sqrt((p*(1-p)/n)
False - because each machine will have different natural tolerances.

45. What quality tool formally incorporates the voice of the customer?
QFD
Mistake-proofing.
The ability of a process to consistently meet customer specifications.
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.

46. What is the center line of an X-bar chart?
Controlling quality at the source.
A scatterplot.
False - because each machine will have different natural tolerances.
X-bar-bar

47. What is a spaghetti diagram?
A tool that shows the physical flows through a space.
The degree to which a product meets pre-established standards.
Prevention - appraisal - internal failure - external failure.
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.

48. What is the center line of a p-chart?
Deming.
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.
To monitor a process when measurement by variables is used.
p-bar - the long-run percent defective.

49. Define aesthetic quality.
The manager in charge of a process being improved in a Six Sigma project.
The cycle time required to meet demand.
Pleasing to the senses.
Prediction and estimation. based on an unknown x value - estimation is based on a known x value

50. If your process is capable at two sigma - what percentage of the output will be defective (assuming the process is in control)?
Mean time to failure.
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
Method developed by Ishikawa to graphically display the causes of any given problem
5%