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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. In a regression - what does the standard error of the estimate tell you?
Observed variation in response is caused by the input
No -- if it is not the same - it can only be worse!
The gap between what is promised and what is delivered.
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.

2. For what is a p-chart used?
An assertion or conjecture concerning one or more populations
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
Shows the temporal flow of activities in a project network.
To monitor a process when measurement by attribute is used.

3. What do you do when a process is out of control?
Mean time to failure.
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
To manage the Six Sigma project.
Look for the assignable cause of non-random variation.

4. Define performance quality.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
The primary operating characteristics of a product.
Sampling for SPC is done real time.
A descending order-sorted bar chart with a cumulative percentage line.

5. In the Service Quality Gap Model - what is Gap 4?
The gap between what is promised and what is delivered.
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan
To be a member of a Six Sigma project team.
A brainstorming tool that shows the connections between ideas.

6. 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?
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
False - because each machine will have different natural tolerances.
Kaoru Ishikawa.
Define - measure - analyze - design - verify.

7. What is a dashboard?
Mean time to replacement.
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
A tool that shows performance along key dimensions all at once.
0.9^3 or 72.9%

8. What does Crosby say about benchmarking?
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
The Japanese national quality award.
99.73%

9. Regression Analysis
The degree to which a product meets pre-established standards.
Different types of defects are listed (used for Pareto chart)
Upper control limit.
Technique used to relate through a model - one or more independent variables and a dependent variable (response)

10. Residual
Shows the temporal flow of activities in a project network.
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.

11. Affinity Diagrams
Linearity - normality - homoscedasticity - independence.
A scatterplot.
Organize ideas into meaningful categories by recognizing their underlying similarity
Defects Per Million Opportunities

12. What quality tool formally incorporates the voice of the customer?
Waste.
Fractional factorial designs (orthogonal arrays)
QFD
Critical to quality.

13. Design of Experiments (DOE) approach
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
Mistake-proofing.
Scrap - rework - retest - downtime - yield losses - disposition costs.
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions

14. Daniel Test
Attribute
3.4 (assuming 1.5 sigma shift in the mean)
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:
Fishbone - cause-and-effect diagram.

15. What is Little's Law?
To be a member of a Six Sigma project team.
Studying firms with the best performance in a particular area.
Inventory = throughput x flow time.
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.

16. Which type of SPC measurement is more precise - variable or attribute?
The target number of standard deviations from the mean for specifications.
Represents the behavior of a process
Variable.
A random variable that summarizes the information from the sample(s).

17. Risk Priority Number RPN
= yij - y(bar)i --> value minus sum of that treatment (of row)
Because the mean and standard deviation are independent of each other.
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
Sampling for SPC is done real time.

18. What is a histogram?
Stratify a particular defect type according to logical criteria
Blame.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
F_alpha - df(tr) - df (error)

19. Define perceived quality (Garvin's framework).
Central Limit Theorem
Brand image.
Rapid improvement process.
Used to create frequency distribution tally sheets

20. What does the abbreviation LCL stand for?
It's good -- but it's still out of control!
The Japanese national quality award.
Lower control limit.
The gap between what management thinks customers want and the process specifications.

21. What is a network diagram?
50%
A diagram that shows the relationships between activities in a project network.
Supplier - input - process - output - customer.
A scatterplot.

22. List two components of prevention cost.
Method developed by Ishikawa to graphically display the causes of any given problem
Lower control limit.
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.
Controlling quality at the source.

23. Cause and Effect Diagrams
The gap between what customers expect and the service they receive.
95%
Method developed by Ishikawa to graphically display the causes of any given problem
To obtain a certain desirable outcome from the process

24. If a Cp shows that a process is not capable - should you calculate Cpk?
Is the consequence of the failure.
No -- if it is not the same - it can only be worse!
The House of Quality.
Hold all input variables constant except one. Observe the response as you vary the single input.

25. What quality guru emphasizes management as a system?
Observed variation in response is caused by the input
Deming.
The primary operating characteristics of a product.
Attribute.

26. Approximately what percent of a normal distribution falls between ± 1 standard deviations from the mean?
Shifts - Trends - Repeating patterns - Correlation with known events
Initiated before or at design concept finalization
Producer risk.
68%

27. How are LQL and AQL determined in an acceptance sampling plan?
If the Response vs. Levels graph if the response lines are not parallel (crossing)
Through producer/consumer negotiation.
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 degree to which a product meets pre-established standards.

28. Test for Independence
The US national quality award.
To obtain a certain desirable outcome from the process
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
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

29. What is Value Stream Mapping?
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
Mean time to replacement.
A tool that shows where there is waste in a process.

30. Does it ever make sense to accept a job when a process is incapable?
The gap between what customers expect and the service they receive.
Workers - machines - materials.
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
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

31. What is Type 1 Error?
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
Reliability - Assurance - Responsiveness - Tangibles - Empathy
Concluding there has been an effect/change when there has not.

32. What are the four perspectives of the Balanced Scorecard?
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
Financial - customer - internal process - innovation and learning.
Supplier - input - process - output - customer.
Method developed by Ishikawa to graphically display the causes of any given problem

33. An SPC chart shows no points outside the control limits. Does this mean the process is in control?
Observed variation in response is caused by the input
100%
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
No -- the variation also has to be random and "expected."

34. What does a project prioritization matrix do?
Assigns scores to weighted criteria for each project under consideration.
Fitness for use.
Is the way in which the failure is manifested.
The ratio of outputs to inputs; 1-scrap.

35. Histogram by Hand
QFD
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
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.
Walter A. Shewhart

36. If you can only collect categorical data - what type of SPC charting can you do?
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.
The gap between specifications and how service is performed.
Lean is waste reduction - Six Sigma is variation reduction.
Attribute.

37. What is FMEA?
Failure Modes and Effects Analysis
Look for the assignable cause of non-random variation.
Waste.
3.4 (assuming 1.5 sigma shift in the mean)

38. Pareto Analysis
The process of ranking opportunities to determine which of many potential opportunities should be pursued first.
50%
False - because each machine will have different natural tolerances.
Variable.

39. With Six Sigma capability - how many defects per million opportunities would you see?
An assertion or conjecture concerning one or more populations
To do a capability study for a non-centered process.
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
3.4 (assuming 1.5 sigma shift in the mean)

40. Which quality guru developed the concept of loss to society?
The Japanese national quality award.
Taguchi
Waste.
The gap between what management thinks customers want and what customers really want.

41. FMEA
It looks to minimize the probability of a failure - or to minimize its effects
F_alpha - df(tr) - df (error)
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
The ratio of outputs to inputs; 1-scrap.

42. What does SIPOC stand for?
Is the way in which the failure is manifested.
Supplier - input - process - output - customer.
Fishbone - cause-and-effect diagram.
Prevention and appraisal costs are balanced against internal and external failure.

43. List two components of internal failure.
Look for the assignable cause of non-random variation.
Scrap - rework - retest - downtime - yield losses - disposition costs.
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
100%

44. When is Cpk used?
To do a capability study for a non-centered process.
Concluding there has been an effect/change when there has not.
Fewer good units to sell - increased variable cost/unit.
To be a member of a Six Sigma project team.

45. If your process is capable at two sigma - what percentage of the output will you have to inspect to find defectives?
Controlling quality at the source.
100%
=sqrt((p*(1-p)/n)
Look for the assignable cause of non-random variation.

46. A process is operating "in control." Does this mean the customer's requirements are met?
Failure Modes and Effects Analysis
Brand image.
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
No -- only if the process is also capable.

47. What are the Five Dimensions of Service Quality?
A random variable that summarizes the information from the sample(s).
Reliability - Assurance - Responsiveness - Tangibles - Empathy
Failure Modes and Effects Analysis
The cycle time required to meet demand.

48. Test for constant variance
A scatterplot.
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.
Pleasing to the senses.
Financial - customer - internal process - innovation and learning.

49. What are the four categories of costs in Juran's framework?
Different types of defects are listed (used for Pareto chart)
Prevention - appraisal - internal failure - external failure.
To do a capability study for a non-centered process.
Attribute

50. What are the three main categories of assignable cause?
Workers - machines - materials.
No -- the variation also has to be random and "expected."
Technique used to relate through a model - one or more independent variables and a dependent variable (response)
Method developed by Ishikawa to graphically display the causes of any given problem