Lean Six Sigma Black Belt Measure Phase: Data Analysis Questions and Answers

Question 1

A Black Belt is analyzing data from a manufacturing process to establish a performance baseline.
The dataset is large and appears to have multiple sources of variation.
To better understand the underlying patterns, the Black Belt decides to separate the data based on shift, machine, and operator.
What is this data analysis technique called?

Accepted Answer

Stratification

Answer

Regression Analysis

Answer

Gage R&R

Answer

Hypothesis Testing

Question 2

In the Measure phase, a project team conducted a Gage R&R study to assess the reliability of their measurement system. The study revealed a high percentage of variation attributable to reproducibility. What is the MOST likely cause of this issue?

Accepted Answer

The operational definitions for taking the measurement are unclear or inconsistently applied by different appraisers.

Answer

The measurement instrument requires calibration.

Answer

There is significant variation within the measurements taken by a single appraiser.

Answer

The process being measured is naturally unstable.

Question 3

A Six Sigma team is evaluating a process's ability to meet customer specifications. They calculate a Cpk of 1.5 and a Cp of 2.0. What can be concluded from these process capability indices?

Accepted Answer

The process variation is too wide compared to the specification limits.

Answer

The process is not capable of meeting specifications.

Answer

The process is perfectly centered between the specification limits.

Answer

The process has the potential to be highly capable, but it is currently off-center.

Question 4

Which of the following graphical tools is most appropriate for visualizing the distribution, central tendency, and spread of a continuous dataset, and for identifying potential outliers?

Accepted Answer

Box Plot

Answer

Pareto Chart

Answer

Scatter Plot

Answer

Control Chart

Question 5

A Black Belt is preparing to analyze process data that has been collected. Many statistical tools assume the data follows a normal distribution. Which statistical test should be used to formally verify this assumption?

Accepted Answer

Anderson-Darling test

Answer

t-test

Answer

ANOVA

Answer

Chi-Square test

Question 6

During the data analysis portion of the Measure phase, a team creates a scatter plot that shows a strong positive correlation between ambient temperature in a factory and the number of product defects. What is the next logical step for the team to take?

Accepted Answer

Formulate a hypothesis to test the causal relationship between temperature and defects in the Analyze phase.

Answer

Immediately implement a new cooling system for the factory.

Answer

Conclude that temperature is the definitive root cause of the defects.

Answer

Discard the data as it only shows correlation, not causation.