Lean Six Sigma Green Belt Certification DMAIC: Measure Phase Tools 3

Question 1

A team calculates Pp = 1.45 and Ppk = 0.92 for a new process. What is the most likely explanation?

Accepted Answer

The process has adequate spread but is significantly off-center

Answer

When Pp is acceptable but Ppk is low, it means the process spread is adequate but the mean is shifted away from the target, reducing Ppk.

Question 2

What is the defects per million opportunities (DPMO) for a process operating at 4 sigma?

Accepted Answer

6,210

Answer

A 4-sigma process corresponds to approximately 6,210 DPMO when using the standard Six Sigma convention that assumes a 1.5-sigma shift.

Question 3

In a control chart, which pattern would NOT trigger a Western Electric (WE) rule violation?

Accepted Answer

Alternate points zig-zagging above and below the centerline within 1 sigma

Answer

Alternating zig-zag points within 1 sigma of the centerline is a common cause pattern and does not trigger any Western Electric rule.

Question 4

What does the 'discrimination ratio' in a gauge R&R study tell practitioners?

Accepted Answer

How many distinct categories the gauge can reliably distinguish in the data

Answer

The discrimination ratio (also called number of distinct categories, NDC) indicates how many statistically distinct groups the measurement system can differentiate in the process variation.

Question 5

A practitioner uses stratified sampling by shift (day, evening, night) and takes equal samples from each. This approach ensures:

Accepted Answer

Representation from each subgroup is guaranteed

Answer

Stratified sampling divides the population into subgroups (strata) and samples from each, ensuring all groups are represented in the dataset.

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification DMAIC: Measure Phase Tools 3