What the Six Sigma Exam Covers
Six Sigma certifications test your command of the DMAIC framework, statistical process control, lean tools, and root cause analysis. Both Green Belt and Black Belt content is covered.
The DMAIC Framework
Six Sigma Exam FAQ
What is the Lean Six Sigma Green Belt exam?
The Lean Six Sigma Green Belt (LSSGB) is a certification that demonstrates competency in the DMAIC problem-solving methodology and basic statistical tools. Major certifying bodies include ASQ (American Society for Quality), IASSC, and Villanova. Exam format varies by body: ASQ's CSSGB has 110 questions in 4.5 hours; IASSC's ICGB has 100 questions in 3 hours.
What is the difference between Green Belt and Black Belt?
Green Belts lead improvement projects part-time alongside their regular roles. Black Belts are dedicated full-time Six Sigma practitioners who lead complex, high-impact projects and mentor Green Belts. The Black Belt exam tests advanced statistics (regression, DOE, ANOVA) and project management at a deeper level than the Green Belt.
How hard is the Six Sigma Green Belt exam?
The ASQ CSSGB has a pass rate of approximately 50–60% for first-time candidates. The exam requires both conceptual understanding of statistical tools and the ability to apply them to real process scenarios. Candidates who study 80–120 hours and practice statistical calculations consistently achieve higher pass rates.
Do I need to know statistics for Six Sigma?
Yes — statistics is the foundation of Six Sigma. For the Green Belt you must understand process capability (Cp, Cpk), control charts (when to use X-bar-R vs. X-bar-S vs. P vs. C charts), basic hypothesis testing (t-tests, chi-square, ANOVA at a conceptual level), and normal distribution. The Black Belt exam requires a deeper applied statistics background.
What is the DMAIC methodology?
DMAIC is the Six Sigma problem-solving framework: Define (define the problem, project scope, and customer requirements — CTQ), Measure (baseline the process — data collection, measurement system analysis), Analyse (identify root causes — fishbone, 5 Whys, hypothesis testing), Improve (implement and verify solutions — DOE, pilot), Control (sustain the gains — control charts, control plan, standardisation).