Lean Six Sigma Green Belt Certification Lean Six Sigma Green Belt Analyze Phase Tools 1

Question 1

What is the primary purpose of a fishbone (Ishikawa) diagram in the Analyze phase?

Accepted Answer

To identify and organize potential root causes of a defect or problem

Answer

The fishbone diagram structures potential causes into categories (such as Man, Machine, Method, Material, Measurement, and Environment) so teams can systematically brainstorm and organize root causes rather than treating them as an unstructured list.

Question 2

In a one-way ANOVA, which statistical measure is being compared across the groups?

Accepted Answer

The means of each group

Answer

ANOVA (Analysis of Variance) tests whether the means of three or more groups are statistically equal by partitioning total variation into within-group and between-group components and comparing them via an F-ratio.

Question 3

What does the R-squared (R²) value indicate in a simple linear regression output?

Accepted Answer

The proportion of total variation in Y that is explained by X

Answer

R-squared, or the coefficient of determination, quantifies how much of the variability in the response variable (Y) is accounted for by the predictor variable (X) in the regression model. A value of 1.0 means the model explains all variation.

Question 4

A multi-vari chart is primarily used in the Analyze phase to:

Accepted Answer

Identify and compare multiple families of variation (within-unit, unit-to-unit, time-to-time)

Answer

Multi-vari charts graphically reveal the dominant source of variation by displaying within-piece, piece-to-piece, and time-to-time variation simultaneously, allowing the team to focus detailed statistical analysis on the right family of variation.

Question 5

A process has a Cpk of 0.85. What does this indicate?

Accepted Answer

The process is not capable of consistently producing output within specification limits

Answer

A Cpk below 1.00 means the process is not capable — it will produce defects outside specification limits. A Cpk of at least 1.33 is typically required to demonstrate adequate short-term capability, and 1.67 or higher for critical characteristics.

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification Lean Six Sigma Green Belt Analyze Phase Tools 1