Lean Six Sigma Black Belt Certification Assessment 4

Question 1

A team is assessing a transactional process and wants to quantify how much time is spent on value-added versus non-value-added activities. Which metric is most appropriate?

Accepted Answer

Process cycle efficiency (PCE)

Answer

Process cycle efficiency = Value-Added Time / Total Lead Time, and in lean transactional processes it is typically well below 10%, indicating significant waste.

Question 2

During an attribute agreement analysis, an appraiser's within-appraiser agreement is 100% but their agreement with the standard (known truth) is only 60%. This indicates:

Accepted Answer

The appraiser is consistent but inaccurate—a systematic bias exists

Answer

High within-appraiser agreement with low accuracy means the appraiser is consistently making the same wrong classification—a systematic error, not random variation.

Question 3

Which statistical test is most appropriate to assess whether a process mean has shifted between two time periods using continuous data that is normally distributed?

Accepted Answer

Two-sample t-test

Answer

The two-sample t-test compares the means of two independent, normally distributed populations to determine if a statistically significant shift has occurred.

Question 4

A Black Belt discovers that the control chart used for baseline assessment had subgroup sizes of 1. Which chart type should have been used?

Accepted Answer

Individuals and Moving Range (I-MR) chart

Answer

When subgroup size is 1 (individual measurements), the I-MR chart is used, tracking individual values and the moving range between consecutive points.

Question 5

In a process capability assessment, the short-term capability (Cp) is 2.0. Assuming the standard 1.5 sigma process drift, what is the expected long-term DPMO?

Accepted Answer

3.4 DPMO

Answer

A short-term Cp of 2.0 corresponds to a 6-sigma process; accounting for the 1.5-sigma long-term shift yields a long-term sigma level of 4.5, which equates to approximately 3.4 DPMO.

Lean Six Sigma Black Belt Certification Practice Test

Lean Six Sigma Black Belt Certification Practice Test

Lean Six Sigma Black Belt Certification Assessment 4