Certified Six Sigma Black Belt Exam Certified Six Sigma Black Belt Trivia 1

Question 1

What is the term for the ratio of the specification width to the process spread, used to measure process capability?

Accepted Answer

Cp Index

Answer

The Cp index (process capability index) measures the ratio of the specification width (USL - LSL) to the process spread (6σ), indicating how well a process fits within its specification limits without regard to centering.

Question 2

In a control chart, what does the term 'common cause variation' describe?

Accepted Answer

Variation inherent to the process operating normally

Answer

Common cause variation (also called natural or random variation) is the inherent, predictable variation present in any stable process. It is distinguished from special cause variation, which arises from assignable, non-routine sources.

Question 3

Which Six Sigma metric accounts for the cumulative probability that all process steps produce defect-free output?

Accepted Answer

Rolled Throughput Yield (RTY)

Answer

Rolled Throughput Yield (RTY) is calculated by multiplying the first-pass yield of each process step together. It reveals the true probability that a unit passes through all steps without any defects or rework.

Question 4

In hypothesis testing, what is the consequence of committing a Type II error?

Accepted Answer

Failing to detect a real effect that exists

Answer

A Type II error (beta error) occurs when the null hypothesis is not rejected even though it is actually false — meaning a real effect or difference goes undetected. This is distinct from a Type I error, which is incorrectly rejecting a true null hypothesis.

Question 5

What is the primary objective of a Gauge Repeatability and Reproducibility (Gauge R&R) study?

Accepted Answer

To quantify the amount of variation contributed by the measurement system

Answer

A Gauge R&R study evaluates how much of the total observed variation is attributable to the measurement system itself (repeatability = same operator, same gauge; reproducibility = different operators). This ensures the measurement system is adequate before analyzing process data.

Certified Six Sigma Black Belt Exam Practice Test

Certified Six Sigma Black Belt Exam Practice Test

Certified Six Sigma Black Belt Exam Certified Six Sigma Black Belt Trivia 1