Lean Six Sigma Black Belt Sample Paper 2: Improve

1. The operators of a manufacturing cell work out a more orderly arrangement for tool storage and establish a schedule to maintain cleanliness daily. These improvements are best described by which approach to problem solving?

5S

Visual aids

Poka yoke

SMED

2. Power of the design can be increased by:

Replicating the center points

Replicating the corner points

Both of the above

None of the above

3. The correct sequence in a DoE study is

Design selection -> Brainstorm factors -> Decide response(s) -> Determine optimal settings of factors for desired response -> Conduct experiments

Design selection -> Decide response(s) -> Brainstorm factors -> Conduct experiments -> Determine optimal settings of factors for desired response

Decide response(s)-> Brainstorm factors -> Conduct experiments -> Fit data into design -> Determine optimal settings of factors for desired response

Decide response(s) -> Finalize factors & their levels-> Design selection -> Conduct experiments - > Determine optimal settings of factors for desired response

4. In a fractional factorial design, the 2 factor interactions (2FI) are confounded with other 2FI’s. What is the resolution of this design

Resolution III

Resolution IV

Resolution V

Resolution VI

5. Two drugs A & B were evaluated for their effectiveness. However, drug A was tested only in individuals with <30 years age and drug B was tested only in individuals with >30 years age. In such a case the effect of the drugs and age of the individuals is said to be

Blocked

Confounded

Folded

Replicated

6. Calculate the effect of factor “B” if

65

-65

5

-5

7. One of the following is not correctly matched to its purpose

Replication: Understand sources of variability that are not seen in repeat measurements

Center point: Understand the effect of hard-to-change factors

Blocking: Technique to include other factors in our experiment which might contribute to undesirable variation.

Randomization: Eliminate effects of unknown or uncontrolled variables

8. If the effect of factor A is 10, it means

When A changes from high to low, the response on an average increases by 10

When A changes from low to high, the response on an average decreases by 10

Both of the above

None of the above

9. With respect to DoE, “Block” for_________ factors and “Randomize” for__________factors

known nuisance, unknown noise

unknown noise, known nuisance

known nuisance, known noise

unknown nuisance, unknown noise

10. The disadvantage of using Pugh Matrix is:

A datum is required to create the matrix

Each alternative is compared to the datum but not to other alternatives

The extent of bettering or worsening is not factored in the calculations

All the above

11. Hindering CTQ’s from HoQ can be optimized to achieve the “Sweet spot” using: (Sweet Spot: Targets for multiple CTQ’s are achieved):

Design of Experiments

De Bono six thinking hats

QFD

Pugh Matrix

12. To check if the relationship between X & Y exhibits curvature (non-linearity) we introduce_______in the design

Center point(s)

Block(s)

Randomization

Folding

13. Determine the number of runs that would be required if we had 3 factors, 2 levels, 2 replicates of the corner points, 3 Center points and 1 block.

33

19

27

22

14. All the pairs below are incorrectly matched, EXCEPT

Full factorial design: Changing one variable at a time (keeping others constant) to understand the impact on the output

Trial and Error: Randomly changing multiple inputs to observe changes to output

Fractional factorial design: Running all factors at all levels and developing a model

One-factor at a time: Running a subset of the full factorial design

15. One of the following DoE can be preferably used as a screening design?

Completely randomized full factorial design with center points

Replicated factorial

Multilevel factorial

Fractional factorial

16. Which of the following is an example of a pilot?

Prototypes developed for early evaluation by end users

Implementation at one work area/region

Test marketing

All the above

17. With respect to an interaction existing between two factors, one of the following is TRUE about the interaction plot:

The plot will show two overlapping lines representing the low and high levels of one of the factors

The plot will show two parallel line representing the low and high levels of one of the factors

The plot will show two non-parallel lines representing the low and high levels of one of the factors, which may or may not be intersecting

All the above scenarios are possible

18. To assess the significance of factors in either a fractional or a full-factorial design, a black belt can use the_________in Minitab

Half-normal plot of effects

ANOVA table

Pareto plot of effects

All the above

19. One factor at a time studies would not be able to identify interactions between the factors as compared to full factorial designs. The statement is:

False

True

True, only if center points are included in the design

Cannot comment until resolution is known

20. Statements given below are true, EXCEPT:

In Resolution III designs, the main effects are confounded with 2 FI’s

In Resolution IV designs, the main effects are confounded with 3 FI’s

The maximum resolution in fractional factorial designs is Resolution V

Low resolution designs can serve the purpose of screening rather than optimization if we have many factors

21. Calculate the interaction effect (AB) for the following data and match with the appropriate statement

0; There is a strong interaction between A & B

0; There is no interaction between A & B

20; There is an interaction between A & B

80; There is an interaction between A & B

22. What resolution will you choose to perform a two-level fractional factorial design; 6 factors, 2 replicates necessary; if the budget doesn’t allow more than 20 experiments

IV

VI

II

III

23. All the following statements regarding reduction of a model for 3 factors (A,B & C) are true, EXCEPT:

Insignificant C can be dropped even if BC is significant

Insignificant AB can be dropped even if A and B are significant

AC can be significant even if A and B are insignificant

If ABC is significant, then no model reduction can be done.

24. One of the following statements is incorrect:

a. DoE is done preferably using historical data

b. Multiple Regression can be run on available historical data

c. Interactions can be better identified from data generated through designed experiments

d. DoE is a better approach than One-factor at a time (OFAT)

25. Residual is an estimate of experimental error obtained by subtracting the ________ from the_________.

Common cause, Special cause

Sigma level (Long term), Sigma level (Short term)

Observed value, Predicted value

Mean, USL

26. An experimental run is conducted several times for the same treatment combination to neutralize the effect of any uncontrollable, unknown factor. This is called___________. However, conducting repeated runs at the same experimental conditions (with a time gap in most cases) is called__________.

Replication, Repetition

Repetition, Replication

Reproducibility, Repeatability

Randomization, Blocking