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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. If a Cp shows that a process is not capable - should you calculate Cpk?
=sqrt((p*(1-p)/n)
No -- if it is not the same - it can only be worse!
The number of standard deviations some value is from the mean.
=sqrt(Σ(x-x-bar)^2)/(n-1))

2. Residual(eij)
Studying firms with the best performance in a particular area.
= yij - y(bar)i --> value minus sum of that treatment (of row)
Scrap - rework - retest - downtime - yield losses - disposition costs.
Upper control limit.

3. If you can only collect categorical data - what type of SPC charting can you do?
A scatterplot.
To monitor a process when measurement by variables is used.
Attribute.
Technical quality is the "what" of the service; functional quality is the "how."

4. Which type of SPC measurement is more precise - variable or attribute?
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Scrap - rework - retest - downtime - yield losses - disposition costs.
Variable.
Can't tell without a Range chart.

5. List two appraisal costs.
Mean time to replacement.
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:
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed

6. What is a network diagram?
Through producer/consumer negotiation.
Look for the assignable cause of non-random variation.
Is the consequence of the failure.
A diagram that shows the relationships between activities in a project network.

7. In a Z table - what is Z?
To manage the Six Sigma project.
Mistake-proofing.
The number of standard deviations some value is from the mean.
A diagram that shows the relationships between activities in a project network.

8. When yields decrease - what are the two effects on contribution?
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
Defects Per Million Opportunities
Central Limit Theorem
Fewer good units to sell - increased variable cost/unit.

9. Residual
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).
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
Variable.

10. Approximately what percent of a normal distribution falls between ± 2 standard deviations from the mean?
The gap between what customers expect and the service they receive.
95%
To monitor a process when measurement by variables is used.
Assigns scores to weighted criteria for each project under consideration.

11. What is Type II Error?
Controlling quality at the source.
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.
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
Concluding there has not been an effect/change when there has.

12. What is process capability?
Speed - courtesy - competence - and ease of repair.
The House of Quality.
Kaoru Ishikawa.
The ability of a process to consistently meet customer specifications.

13. Simple Regression Analysis (one factor regression model)
Workers - machines - materials.
The Japanese national quality award.
= 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
The ability of a process to consistently meet customer specifications.

14. What is the difference between Lean and Six Sigma?
Lean is waste reduction - Six Sigma is variation reduction.
The US national quality award.
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 mentor/coach (and sometimes train) black belts.

15. When Crosby said - "Quality is free -" what dimension of quality was he referring to?
Mean time to replacement.
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.
Define - measure - analyze - improve - control.
Conformance to specifications.

16. Who first studied randomness in industrial processes
Walter A. Shewhart
Consumer risk.
The degree to which a product meets pre-established standards.
Rapid improvement process.

17. Defect location check sheets
Actual drawings - layouts - maps - etc which show where a defect occurs
Controlling quality at the source.
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
Walter A. Shewhart

18. List two components of external failure.
Scrap - rework - retest - downtime - yield losses - disposition costs.
Complaint adjustment - returned material - warranty charges - allowances - loss of future business.
A diagram that shows the relationships between activities in a project network.
Failure Modes and Effects Analysis

19. What is a Pareto chart?
Defects Per Million Opportunities
QFD
A descending order-sorted bar chart with a cumulative percentage line.
100%

20. How does Juran define quality?
Is the way in which the failure is manifested.
X-bar-bar
=sqrt((p*(1-p)/n)
Fitness for use.

21. What is poka yoke?
The target number of standard deviations from the mean for specifications.
50%
Blame.
Mistake-proofing.

22. What inventory approach contributes to process quality by "lowering the river to find the rocks?"
The number of standard deviations some value is from the mean.
Financial - customer - internal process - innovation and learning.
Lean (or JIT).
What the value of the dependent variable is when the independent variable is zero.

23. List Garvin's eight dimensions of product quality.
Fewer good units to sell - increased variable cost/unit.
X-bar-bar
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.

24. Regression
Represents the behavior of a process
95%
Because the mean and standard deviation are independent of each other.
Hold all input variables constant except one. Observe the response as you vary the single input.

25. What is a Gantt chart?
Shows the temporal flow of activities in a project network.
68%
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables
5%

26. Regression Analysis
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.
Technique used to relate through a model - one or more independent variables and a dependent variable (response)
Shifts - Trends - Repeating patterns - Correlation with known events
Controlling quality at the source.

27. For what is a p-chart used?
Fishbone - cause-and-effect diagram.
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
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 attribute is used.

28. What is CTQ?
Fractional factorial designs (orthogonal arrays)
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
Walter A. Shewhart
Critical to quality.

29. What does the abbreviation UCL stand for?
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
100%
50%
Upper control limit.

30. Name the structure associated with Quality Function Deployment.
A tool that shows where there is waste in a process.
The House of Quality.
Is what induces the failure
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.

31. What is Kaizen?
Rapid improvement process.
The degree to which a product meets pre-established standards.
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables

32. Defect check sheets
What the value of the dependent variable is when the independent variable is zero.
Reliability - Assurance - Responsiveness - Tangibles - Empathy
To monitor a process when measurement by attribute is used.
Different types of defects are listed (used for Pareto chart)

33. Define takt time.
Prevention - appraisal - internal failure - external failure.
The cycle time required to meet demand.
It's good -- but it's still out of control!
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.

34. What is the center line of a p-chart?
The US national quality award.
Scrap - rework - retest - downtime - yield losses - disposition costs.
The degree to which a product meets pre-established standards.
p-bar - the long-run percent defective.

35. TWO-DIMENTIONAL SCATTER PLOT
Walter A. Shewhart
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
An assertion or conjecture concerning one or more populations
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables

36. Define product reliability.
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
No -- the variation also has to be random and "expected."
Mean time to failure.
0.9^3 or 72.9%

37. When either attribute or variable measures could be used for SPC - why might attribute measurement be preferred?
Lean is waste reduction - Six Sigma is variation reduction.
Lower skill requirements - faster - less chance for error.
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
= yij - y(bar)i --> value minus sum of that treatment (of row)

38. One factor at a time (OFAT)
Not necessarily.
The gap between specifications and how service is performed.
Hold all input variables constant except one. Observe the response as you vary the single input.
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions

39. What size should samples be for attribute SPC?
An assertion or conjecture concerning one or more populations
Large enough to find two of the attribute - on average.
Fewer good units to sell - increased variable cost/unit.
Studying firms with the best performance in a particular area.

40. Based on what principal can we use the normal distribution assumptions for SPC?
Lower control limit.
Central Limit Theorem
Decomposing the total variation of data into: (a) the internal or "natural" or "within" groups variation - and (b) the "between" groups variation in such a way that when these two types of variation are compared - it's possible to determine if there
= 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

41. Risk Priority Number RPN
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
Failure Modes and Effects Analysis
Attribute.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.

42. Define aesthetic quality.
Speed - courtesy - competence - and ease of repair.
Defects Per Million Opportunities
Pleasing to the senses.
Taguchi

43. What happens to control limits on an SPC chart when sample size is increased?
The ratio of outputs to inputs; 1-scrap.
An assertion or conjecture concerning one or more populations
Causes that lead to a particular effect.
They move closer to the center line.

44. You have been plotting sample means on an x-bar chart and all points indicate normal - expected variation. Is the process in control?

45. Uses of regression
If the Response vs. Levels graph if the response lines are not parallel (crossing)
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
Because the mean and standard deviation are independent of each other.
Concluding there has not been an effect/change when there has.

46. What is the center line of an X-bar chart?
=sqrt(Σ(x-x-bar)^2)/(n-1))
Studying firms with the best performance in a particular area.
X-bar-bar
Decomposing the total variation of data into: (a) the internal or "natural" or "within" groups variation - and (b) the "between" groups variation in such a way that when these two types of variation are compared - it's possible to determine if there

47. What are two other names for an Ishikawa diagram?
Sort - Set in Order - Shine - Standardize - Sustain
Fishbone - cause-and-effect diagram.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
Kaoru Ishikawa.

48. In the Service Quality Gap Model - what is Gap 4?
The degree to which a product meets pre-established standards.
Variable.
The gap between what is promised and what is delivered.
Stratify a particular defect type according to logical criteria

49. ANOVA

50. Failure Mode
Assigns scores to weighted criteria for each project under consideration.
What the value of the dependent variable is when the independent variable is zero.
Is the way in which the failure is manifested.
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality