Lean Six Sigma Black Belt Certification Assessment 3

Question 1

A Black Belt wants to assess whether a process is in statistical control before calculating capability indices. Which tool is most appropriate?

Accepted Answer

Control chart

Answer

Capability indices are only meaningful when the process is stable; a control chart must confirm the absence of special-cause variation before computing Cp or Cpk.

Question 2

Which formula correctly defines process sigma level from defects per million opportunities (DPMO)?

Accepted Answer

Sigma = NORMSINV(1 - DPMO/1,000,000) + 1.5

Answer

Process sigma is calculated by converting DPMO to a Z-value using the inverse normal CDF and adding the 1.5 sigma long-term shift adjustment.

Question 3

During baselining, a Black Belt calculates a rolled throughput yield (RTY) of 0.62 across four process steps. What does this mean?

Accepted Answer

62% of units complete all four steps without any defect

Answer

RTY is the probability that a unit passes through all process steps without requiring rework or being defective; 0.62 means 62% of units are defect-free throughout.

Question 4

Which assessment tool maps the current state of a process by depicting all activities, delays, and information flows to identify waste?

Accepted Answer

Value Stream Map

Answer

A Value Stream Map (VSM) visualizes material and information flows with cycle times, wait times, and inventory counts, making waste visible for elimination.

Question 5

A measurement system shows acceptable Gage R&R %Study Variation but fails the bias test. What is the best corrective action?

Accepted Answer

Calibrate or adjust the measurement instrument

Answer

Bias (systematic error) indicates the measurement system consistently reads high or low relative to the true value, which is corrected by calibration or instrument adjustment.

Lean Six Sigma Black Belt Certification Practice Test

Lean Six Sigma Black Belt Certification Practice Test

Lean Six Sigma Black Belt Certification Assessment 3