Lean Six Sigma Black Belt Certification Lean Six Sigma Black Belt Define and Measure Phases 1

Question 1

A Black Belt wants to visually display the sequence of steps in a customer order fulfillment process, including handoffs between departments and wait times. Which tool is most appropriate?

Accepted Answer

Value Stream Map

Answer

A Value Stream Map (VSM) captures material and information flow, process steps, cycle times, and wait times across departments, making it ideal for identifying non-value-added activities during the Define/Measure phases.

Question 2

During the Measure phase, a Black Belt collects 25 subgroups of 5 samples each to establish process baselines. Which control chart pair is most appropriate for monitoring the process mean and variation?

Accepted Answer

X-bar and R chart

Answer

The X-bar and R chart is the standard choice for subgroup data with a fixed sample size (n=2–10), tracking both the subgroup mean (X-bar) and range (R) to monitor central tendency and spread simultaneously.

Question 3

A project charter is being reviewed and the team notices the problem statement reads: 'We need to implement a new ERP system to fix customer complaints.' What is wrong with this statement?

Accepted Answer

It presupposes a solution rather than describing the problem objectively

Answer

A well-written problem statement describes what is wrong and its impact without prescribing a solution. Jumping to 'implement an ERP system' closes off root-cause analysis before the DMAIC process has even begun.

Question 4

A Black Belt performs a Gauge R&R study and finds that %Gauge R&R is 28%. How should this measurement system be classified?

Accepted Answer

Marginally acceptable — use with caution and consider improvement

Answer

Industry guidelines classify %Gauge R&R below 10% as acceptable, 10–30% as marginal (may be acceptable depending on application), and above 30% as unacceptable. At 28%, the system falls in the marginal zone, warranting caution.

Question 5

Which formula correctly expresses process yield in terms of Defects Per Unit (DPU) for a Poisson-distributed defect model?

Accepted Answer

Y = e^(−DPU)

Answer

Assuming Poisson distribution of defects, the first-pass yield is Y = e^(−DPU). This formula is foundational for calculating Rolled Throughput Yield (RTY) across multiple process steps.

Lean Six Sigma Black Belt Certification Practice Test

Lean Six Sigma Black Belt Certification Practice Test

Lean Six Sigma Black Belt Certification Lean Six Sigma Black Belt Define and Measure Phases 1