Six Sigma Green Belt Flashcards

In Six Sigma, what does the term 'sigma level' measure?

Answer: The number of standard deviations between the process mean and the nearest specification limit

Sigma level indicates how many standard deviations fit between the process mean and the nearest specification limit, reflecting process capability.

Which tool is used in the Define phase to identify all stakeholders and their requirements for a Six Sigma project?

Answer: SIPOC diagram

The SIPOC diagram maps Suppliers, Inputs, Process, Outputs, and Customers, helping define project scope and stakeholder requirements during the Define phase.

What is the purpose of a Gage R&R study in the Measure phase?

Answer: To evaluate the repeatability and reproducibility of a measurement system

Gage R&R quantifies how much of the observed process variation is due to measurement error versus actual process variation.

A process has a Cp of 1.5 but a Cpk of 0.8. What does this indicate?

Answer: The process has adequate potential but is not centered within the specification limits

Cp measures process spread potential while Cpk accounts for centering; a high Cp with low Cpk means the process could be capable if properly centered.

In hypothesis testing, a Type II error (beta error) occurs when:

Answer: A false null hypothesis is not rejected

A Type II error (beta error) is failing to detect a real effect — accepting the null hypothesis when it is actually false.

Which of the following best describes the purpose of stratification in data analysis?

Answer: Separating data into subgroups to identify patterns or sources of variation

Stratification divides data into meaningful subgroups (by shift, machine, operator, etc.) to reveal hidden patterns and root causes of variation.

What is the primary output of the Analyze phase in DMAIC?

Answer: Validated root causes of the problem

The Analyze phase uses statistical and graphical tools to identify and validate the root causes that explain the performance gap defined in earlier phases.