Lean Six Sigma Black Belt Certification Assessment 5

Question 1

A Black Belt assessing a manufacturing process finds OEE of 48%. Which three OEE components multiply to produce this score?

Accepted Answer

Availability × Performance × Quality

Answer

OEE = Availability (planned uptime actually running) × Performance (actual vs. ideal speed) × Quality (good parts vs. total parts produced).

Question 2

During process assessment a team finds that the measurement system's linearity is poor. What does poor linearity indicate?

Accepted Answer

The bias of the measurement system changes across the operating range

Answer

Linearity measures how consistent the bias is across the full range of expected measurements; poor linearity means the instrument's accuracy varies depending on where in the range you measure.

Question 3

When assessing process stability using a control chart, which pattern suggests a special cause related to a gradual process drift or tool wear?

Accepted Answer

Six or more consecutive points trending in one direction

Answer

A sustained trend of six or more consecutive points moving in one direction is a Nelson/Western Electric rule that signals a gradual shift—often caused by wear, fatigue, or drift.

Question 4

A Black Belt uses a cause-and-effect matrix (C&E matrix) to prioritize inputs for further data collection. The matrix scores each process input against:

Accepted Answer

Customer output requirements weighted by their importance rating

Answer

The C&E matrix scores each process input (X) for its impact on each customer-critical output (Y), weighted by the customer's importance rating for that output.

Question 5

Which type of sampling is most appropriate when a process runs in natural groups (e.g., shifts, machines) and the Black Belt wants each group represented proportionally?

Accepted Answer

Stratified random sampling

Answer

Stratified random sampling divides the population into homogeneous subgroups (strata) and samples proportionally from each, ensuring all sources of variation are represented.

Lean Six Sigma Black Belt Certification Practice Test

Lean Six Sigma Black Belt Certification Practice Test

Lean Six Sigma Black Belt Certification Assessment 5