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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. Define product reliability.
They move closer to the center line.
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
Mean time to failure.
Causes that lead to a particular effect.

2. In Juran's Cost of Quality model - which categories of costs balance which other categories?
Prevention and appraisal costs are balanced against internal and external failure.
Fewer good units to sell - increased variable cost/unit.
3.4 (assuming 1.5 sigma shift in the mean)
Taguchi

3. If a three-stage process has 90% yields at each stage - what is the overall yield?
Technique used to relate through a model - one or more independent variables and a dependent variable (response)
0.9^3 or 72.9%
What the value of the dependent variable is when the independent variable is zero.
Reliability - Assurance - Responsiveness - Tangibles - Empathy

4. What is the difference between Lean and Six Sigma?
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
Can't tell without a Range chart.
Lean is waste reduction - Six Sigma is variation reduction.
Outside.

5. What are the 5 Ss?
Hold all input variables constant except one. Observe the response as you vary the single input.
Sort - Set in Order - Shine - Standardize - Sustain
Financial - customer - internal process - innovation and learning.
Prevention and appraisal costs are balanced against internal and external failure.

6. Your production process meets customer specifications. Is your process in control?
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
The US national quality award.
Not necessarily.
Waste.

7. For your SPC sample you weigh bags of potatoes. Is this variable or attribute SPC?
Shows the temporal flow of activities in a project network.
10 if Almost impossible to detect
Conformance to specifications.
Variable.

8. What is DMADV?
Technique used to relate through a model - one or more independent variables and a dependent variable (response)
No -- the variation also has to be random and "expected."
Define - measure - analyze - design - verify.
95%

9. Does it ever make sense to accept a job when a process is incapable?
Waste.
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
A scatterplot.
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).

10. When Crosby said - "Quality is free -" what dimension of quality was he referring to?
Conformance to specifications.
Causes that lead to a particular effect.
The gap between what management thinks customers want and what customers really want.
X-bar-bar

11. List two components of internal failure.
Supplier - input - process - output - customer.
Fractional factorial designs (orthogonal arrays)
Scrap - rework - retest - downtime - yield losses - disposition costs.
Shifts - Trends - Repeating patterns - Correlation with known events

12. Residual(eij)
= 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
Lean (or JIT).
= yij - y(bar)i --> value minus sum of that treatment (of row)
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions

13. Defect location check sheets
Workers - machines - materials.
Actual drawings - layouts - maps - etc which show where a defect occurs
If the Response vs. Levels graph if the response lines are not parallel (crossing)
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median

14. What does DMAIC stand for?
Shifts - Trends - Repeating patterns - Correlation with known events
A brainstorming tool that shows the connections between ideas.
Assigns scores to weighted criteria for each project under consideration.
Define - measure - analyze - improve - control.

15. How are LQL and AQL determined in an acceptance sampling plan?
Consumer risk.
Through producer/consumer negotiation.
Critical to quality.
The target number of standard deviations from the mean for specifications.

16. What are two other names for an Ishikawa diagram?
The ability of a process to consistently meet customer specifications.
Fishbone - cause-and-effect diagram.
p-bar - the long-run percent defective.
Inventory = throughput x flow time.

17. If you have calculated a Cpk - should you also calculate a Cp?
=sqrt(Σ(x-x-bar)^2)/(n-1))
100%
No -- if it is not the same - it can only be worse!
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.

18. Define performance quality.
The primary operating characteristics of a product.
Upper control limit.
= 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
Mean time to failure.

19. DFMEA
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
Mean time to replacement.
Initiated before or at design concept finalization
Studying firms with the best performance in a particular area.

20. Taguchi's experimental designs are of this type.
No -- only if the process is also capable.
5%
Sort - Set in Order - Shine - Standardize - Sustain
Fractional factorial designs (orthogonal arrays)

21. 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?
To monitor a process when measurement by attribute is used.
False - because each machine will have different natural tolerances.
Fishbone - cause-and-effect diagram.
Concluding there has not been an effect/change when there has.

22. Approximately what percent of a normal distribution falls between ± 1 standard deviations from the mean?
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.
Inventory = throughput x flow time.
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
68%

23. Which type of SPC measurement is more precise - variable or attribute?
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
No -- only if the process is also capable.
Variable.
Method developed by Ishikawa to graphically display the causes of any given problem

24. What quality guru emphasizes management as a system?
Mistake-proofing.
Deming.
Producer risk.
Blame.

25. What is the formula for standard deviation?
Technical quality is the "what" of the service; functional quality is the "how."
10 if Almost impossible to detect
Organize ideas into meaningful categories by recognizing their underlying similarity
=sqrt(Σ(x-x-bar)^2)/(n-1))

26. TWO-DIMENTIONAL SCATTER PLOT
Taguchi
Through producer/consumer negotiation.
0.9^3 or 72.9%
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables

27. Definition of Interaction
False - because each machine will have different natural tolerances.
A tool that shows performance along key dimensions all at once.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
Critical to quality.

28. Affinity Diagrams
Organize ideas into meaningful categories by recognizing their underlying similarity
What the value of the dependent variable is when the independent variable is zero.
100%
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).

29. To what does the Six in Six Sigma relate?
The target number of standard deviations from the mean for specifications.
Observed variation in response is caused by the input
Consumer risk.
It looks to minimize the probability of a failure - or to minimize its effects

30. What is a histogram?
50%
Prevention and appraisal costs are balanced against internal and external failure.
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.

31. List two appraisal costs.
A time series plot.
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
Causes that lead to a particular effect.
Actual drawings - layouts - maps - etc which show where a defect occurs

32. Which quality guru developed the concept of loss to society?
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
X-bar-bar
Taguchi
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.

33. What is Type II Error?
Walter A. Shewhart
The gap between specifications and how service is performed.
Method developed by Ishikawa to graphically display the causes of any given problem
Concluding there has not been an effect/change when there has.

34. What is the 5S model?
Outside.
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.
Technical quality is the "what" of the service; functional quality is the "how."
Scrap - rework - retest - downtime - yield losses - disposition costs.

35. Define benchmarking.
Sampling for SPC is done real time.
To be a member of a Six Sigma project team.
Studying firms with the best performance in a particular area.
Pleasing to the senses.

36. Stratified defect check sheets
Stratify a particular defect type according to logical criteria
Not necessarily.
A descending order-sorted bar chart with a cumulative percentage line.
The number of standard deviations some value is from the mean.

37. What is a run chart?
A time series plot.
0.9^3 or 72.9%
Method developed by Ishikawa to graphically display the causes of any given problem
A tool that shows performance along key dimensions all at once.

38. Who first studied randomness in industrial processes
To do a capability study for a non-centered process.
Walter A. Shewhart
A brainstorming tool that shows the connections between ideas.
Observed variation in response is caused by the input

39. What is a dashboard?
Speed - courtesy - competence - and ease of repair.
= 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
p-bar - the long-run percent defective.
A tool that shows performance along key dimensions all at once.

40. A process is operating "in control." Does this mean the customer's requirements are met?
Critical to quality.
Can't tell without a Range chart.
Before production starts
No -- only if the process is also capable.

41. Design of Experiments (DOE) approach
Define - measure - analyze - improve - control.
Inventory = throughput x flow time.
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
Because the mean and standard deviation are independent of each other.

42. Manual Test for Nomality
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
Mean time to failure.
An assertion or conjecture concerning one or more populations
The gap between what management thinks customers want and what customers really want.

43. What size should samples be for attribute SPC?
The gap between what management thinks customers want and the process specifications.
The gap between what management thinks customers want and what customers really want.
Large enough to find two of the attribute - on average.
Outside.

44. What is the difference between the way sampling is done for SPC and for acceptance sampling?
Outside.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
Sampling for SPC is done real time.
Attribute

45. Process occurance ranking
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
Pleasing to the senses.
A tool that shows where there is waste in a process.
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces

46. Define perceived quality (Garvin's framework).
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
p-bar - the long-run percent defective.
Because the mean and standard deviation are independent of each other.
Brand image.

47. F value
F_alpha - df(tr) - df (error)
Organize ideas into meaningful categories by recognizing their underlying similarity
The ability of a process to consistently meet customer specifications.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.

48. Define conformance quality.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
The degree to which a product meets pre-established standards.
Brand image.
Actual drawings - layouts - maps - etc which show where a defect occurs

49. What is the role of a black belt?
If the Response vs. Levels graph if the response lines are not parallel (crossing)
Shifts - Trends - Repeating patterns - Correlation with known events
To manage the Six Sigma project.
To monitor a process when measurement by attribute is used.

50. What are the four categories of costs in Juran's framework?
Rapid improvement process.
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
Prevention - appraisal - internal failure - external failure.
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.