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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 graphical tool is used to show the relationship between two numerical variables?
Walter A. Shewhart
Hold all input variables constant except one. Observe the response as you vary the single input.
A scatterplot.
Consumer risk.

2. Who is a process owner?
Supplier - input - process - output - customer.
No -- the variation also has to be random and "expected."
The manager in charge of a process being improved in a Six Sigma project.
Upper control limit.

3. If you have calculated a Cpk - should you also calculate a Cp?
The Japanese national quality award.
Technical quality is the "what" of the service; functional quality is the "how."
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.
A tool that shows performance along key dimensions all at once.

4. Stratified defect check sheets
Critical to quality.
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
Stratify a particular defect type according to logical criteria
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions

5. What are the 5 Ss?
Central Limit Theorem
Prevention and appraisal costs are balanced against internal and external failure.
Observed variation in response is caused by the input
Sort - Set in Order - Shine - Standardize - Sustain

6. For your SPC sample you weigh bags of potatoes. Is this variable or attribute SPC?
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
No -- only if the process is also capable.
Variable.
Initiated before or at design concept finalization

7. What are the three main categories of assignable cause?
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
Workers - machines - materials.
Fitness for use.
100%

8. What is the difference between the way sampling is done for SPC and for acceptance sampling?
Rapid improvement process.
Outside.
Prevention - appraisal - internal failure - external failure.
Sampling for SPC is done real time.

9. What is a Gantt chart?
Fewer good units to sell - increased variable cost/unit.
Someone who is consistently against virtually everything.
Shows the temporal flow of activities in a project network.
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

10. Does it ever make sense to accept a job when a process is incapable?
A brainstorming tool that shows the connections between ideas.
Variable.
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
A time series plot.

11. Test for Independence
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.
Outside.
Attribute
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

12. Which quality guru developed the concept of loss to society?
What the value of the dependent variable is when the independent variable is zero.
Taguchi
A random variable that summarizes the information from the sample(s).
Look for the assignable cause of non-random variation.

13. What are the four categories of costs in Juran's framework?
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
Prevention - appraisal - internal failure - external failure.
Not necessarily.
Observed variation in response is caused by the input

14. 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?
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
QFD
Through producer/consumer negotiation.
False - because each machine will have different natural tolerances.

15. An SPC chart shows no points outside the control limits. Does this mean the process is in control?
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
No -- the variation also has to be random and "expected."
50%
Is the consequence of the failure.

16. Taguchi's experimental designs are of this type.
Fractional factorial designs (orthogonal arrays)
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.
Fitness for use.
Is what induces the failure

17. Definition of Interaction
10 if Almost impossible to detect
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
10 for Hazardous without warning 1 for none
Lean is waste reduction - Six Sigma is variation reduction.

18. Who developed the fishbone diagram?
A tool that shows the physical flows through a space.
Kaoru Ishikawa.
Attribute
Actual drawings - layouts - maps - etc which show where a defect occurs

19. Define perceived quality (Garvin's framework).
Brand image.
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
Can't tell without a Range chart.
No -- if it is not the same - it can only be worse!

20. When is Cpk used?
To do a capability study for a non-centered process.
To manage the Six Sigma project.
Organize ideas into meaningful categories by recognizing their underlying similarity
To mentor/coach (and sometimes train) black belts.

21. What are the four perspectives of the Balanced Scorecard?
Brand image.
If the Response vs. Levels graph if the response lines are not parallel (crossing)
Outside.
Financial - customer - internal process - innovation and learning.

22. DOE
Reliability - Assurance - Responsiveness - Tangibles - Empathy
The Japanese national quality award.
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan
Is what induces the failure

23. List Garvin's eight dimensions of product quality.
It's good -- but it's still out of control!
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
The gap between what is promised and what is delivered.

24. Effect ranking (Severity of the Defect)
10 for Hazardous without warning 1 for none
The House of Quality.
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.
The gap between what is promised and what is delivered.

25. What is Value Stream Mapping?
The gap between what is promised and what is delivered.
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
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).
A tool that shows where there is waste in a process.

26. What is the role of a master black belt?
A scatterplot.
Defects Per Million Opportunities
To mentor/coach (and sometimes train) black belts.
The gap between what management thinks customers want and what customers really want.

27. Risk Priority Number RPN
50%
Brand image.
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.

28. Process occurance ranking
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
Complaint adjustment - returned material - warranty charges - allowances - loss of future business.
Causes that lead to a particular effect.
Organize ideas into meaningful categories by recognizing their underlying similarity

29. Defect location check sheets
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
X-bar-bar
Actual drawings - layouts - maps - etc which show where a defect occurs
To be a member of a Six Sigma project team.

30. What is CTQ?
Variable.
Shows the temporal flow of activities in a project network.
Critical to quality.
Blame.

31. What does Crosby say about benchmarking?
Sampling for SPC is done real time.
A tool that shows where there is waste in a process.
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
An interaction is defined as a dependence relationship between the response and the levels of two or more variables

32. Define performance quality.
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
The primary operating characteristics of a product.
A tool that shows performance along key dimensions all at once.
=sqrt(Σ(x-x-bar)^2)/(n-1))

33. Approximately what percent of a normal distribution falls between ± 3 standard deviations from the mean?
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
A time series plot.
99.73%
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).

34. Complete this quality phrase: 'Fix the process - not the _____.'
Blame.
10 if Almost impossible to detect
Someone who is consistently against virtually everything.
Shifts - Trends - Repeating patterns - Correlation with known events

35. Why do you need two control charts for variables SPC?
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
Because the mean and standard deviation are independent of each other.
= yij - y(bar)i --> value minus sum of that treatment (of row)
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).

36. What type of risk is associated with Type II Error?
Consumer risk.
Mean time to failure.
Concluding there has been an effect/change when there has not.
Lean is waste reduction - Six Sigma is variation reduction.

37. Daniel Test
Mean time to failure.
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:
Lower skill requirements - faster - less chance for error.
Complaint adjustment - returned material - warranty charges - allowances - loss of future business.

38. When yields decrease - what are the two effects on contribution?
Different types of defects are listed (used for Pareto chart)
A random variable that summarizes the information from the sample(s).
Fewer good units to sell - increased variable cost/unit.
Large enough to find two of the attribute - on average.

39. Based on what principal can we use the normal distribution assumptions for SPC?
50%
Central Limit Theorem
95%
Stratify a particular defect type according to logical criteria

40. What is a dashboard?
The ratio of outputs to inputs; 1-scrap.
3.4 (assuming 1.5 sigma shift in the mean)
A tool that shows performance along key dimensions all at once.
To mentor/coach (and sometimes train) black belts.

41. For what is a p-chart used?
p-bar - the long-run percent defective.
Waste.
To monitor a process when measurement by attribute is used.
Different types of defects are listed (used for Pareto chart)

42. Histogram by Hand
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
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
95%
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables

43. In a regression - what does the standard error of the estimate tell you?
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.
Assigns scores to weighted criteria for each project under consideration.
Used to create frequency distribution tally sheets
The manager in charge of a process being improved in a Six Sigma project.

44. DFMEA
Initiated before or at design concept finalization
False - because each machine will have different natural tolerances.
Not necessarily.
The cycle time required to meet demand.

45. Uses of regression
Is the consequence of the failure.
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
A brainstorming tool that shows the connections between ideas.

46. Residual
Look for the assignable cause of non-random variation.
X-bar-bar
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
Studying firms with the best performance in a particular area.

47. Define takt time.
Sort - Set in Order - Shine - Standardize - Sustain
Organize ideas into meaningful categories by recognizing their underlying similarity
= yij - y(bar)i --> value minus sum of that treatment (of row)
The cycle time required to meet demand.

48. What percentage of a normal distribution lies above the mean?
To do a capability study for a non-centered process.
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
A brainstorming tool that shows the connections between ideas.
50%

49. Affinity Diagrams
To mentor/coach (and sometimes train) black belts.
Initiated before or at design concept finalization
= 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
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions

50. What is a CAVE man?
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.
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
Someone who is consistently against virtually everything.
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: