Lean Six Sigma Green Belt Certification Cheat Sheet 2026

The 30 highest-yield Lean Six Sigma Green Belt Certification facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. When using a Pugh concept selection matrix during the Analyze phase, what does a datum (baseline) represent? → The current process or reference concept against which alternatives are compared
2. Which two components of variation does a Gage R&R study measure? → Repeatability and Reproducibility
3. In a single-minute exchange of die (SMED) initiative, 'external setup' activities are those that: → Can only be done while the machine is running
4. Which VOC collection method is BEST suited for gathering quantitative data from a large customer population? → Structured surveys with rating scales
5. What is the Z-score for a data point that is 2 standard deviations below the mean? → -2
6. A team is comparing average delivery times between three different shipping carriers. Which statistical test is most appropriate? → One-way ANOVA
7. A normal distribution has 99.73% of data within how many standard deviations of the mean? → 3
8. A spaghetti diagram is most useful in the Measure phase for: → Visualizing physical movement of people or materials in a process
9. Which type of control chart would be most appropriate for monitoring the number of defects per unit after implementing improvements? → U-chart
10. A Lean Six Sigma project's authorized written plan detailing the anticipated advantages to the business and anticipated cost savings is known as a → Project business case
11. Which of the following is the best example of a 'pull' system in a manufacturing environment? → Manufacturing products only after receiving a customer order or kanban signal
12. Which of the following activities is considered value-added in a Lean process? → Machining a component to customer-specified dimensions
13. What is the purpose of a box plot (box-and-whisker plot) in data analysis? → To show the five-number summary and identify outliers
14. Which level of measurement allows calculation of ratios and has a true zero point? → Ratio
15. Which chart is most appropriate for tracking a single process metric over time to detect trends or shifts? → Run chart
16. During a Lean Six Sigma assessment, a team calculates process sigma level. A process with a DPMO of 6,210 corresponds to which sigma level? → 4 sigma
17. A process has a Cp of 1.5 but a Cpk of 0.8. What does this indicate? → The process has sufficient spread but is off-center
18. What does the acronym DPMO stand for in Six Sigma? → Defects Per Million Opportunities
19. What is the primary purpose of a Value Stream Map (VSM) in Lean methodology? → To visualize the flow of materials and information and identify waste
20. What does the %Tolerance method in Gage R&R analysis compare? → Measurement system variation as a percentage of the engineering specification tolerance
21. Mistake-proofing (poka-yoke) devices are preferred in the Control phase because they: → Prevent errors from occurring rather than detecting them after the fact
22. In the Define phase, a RACI matrix is primarily used to: → Clarify team member roles and decision-making authority for the project
23. What is the significance of a Cp value greater than 1.33 in process capability analysis? → The process is considered capable with an adequate safety margin
24. A Green Belt uses a regression equation: Y = 12.4 + 3.2X. If X increases by 2 units, what is the predicted change in Y? → 6.4 units
25. What does it mean when a regression model's residuals show a pattern (e.g., funnel shape) when plotted against fitted values? → Heteroscedasticity exists, violating regression assumptions
26. In a cause-and-effect (fishbone) diagram, which of the following is NOT a traditional 6M category? → Money
27. Which statistic is most resistant to the influence of outliers when describing the center of a dataset? → Median
28. A approach called "the voice of the customer" understanding is used to give customers: → Services and products that meet the customer expectations and needs
29. A Lean Six Sigma team uses a 2^3 full factorial experiment with center points. What is the primary reason for adding center points? → To detect curvature in the response and estimate pure error
30. When using a Poka-Yoke (mistake-proofing) device as an improvement solution, the primary goal is to: → Make it impossible or immediately obvious when an error is about to happen