ICGB study guide
ICGB · Work through your exam, one topic at a time.
The IASSC Certified Lean Six Sigma Green Belt (ICGB) is a professional credential for practitioners who are well versed in the core to advanced elements of Lean Six Sigma methodology. Green Belts lead improvement projects or serve as team members on more complex projects led by a Certified Black Belt, typically in a part-time role. The credential requires competence in subject matter across the DMAIC phases-Define, Measure, Analyze, Improve, and Control-as defined by the IASSC Lean Six Sigma Green Belt Body of Knowledge. The exam is a 100-question, closed-book, proctored test with a 3-hour allotted time; some forms may include up to 10 additional non-graded questions. The ICGB study guide has 5 sections and about 1,512 words.
01Define
The Define domain establishes whether a project is worth doing and exactly what problem it will solve. ICGB questions test your ability to turn a vague complaint into a scoped, measurable charter with validated voice of the customer (VOC) and a defensible baseline.
317 words, about 2 min02Measure
The Measure domain quantifies the current process and proves the data are trustworthy. ICGB tests whether you validate the measurement system before calculating baseline capability.
297 words, about 1 min03Analyze
The Analyze domain tests explanations for the gap identified in Define and measured in Measure. ICGB questions ask you to separate real causes from plausible stories and to interpret statistical evidence correctly.
324 words, about 2 min04Improve
The Improve domain generates, selects, pilots, and implements changes that close the verified gap. ICGB tests whether you choose solutions with evidence and confirm improvement rather than assuming it.
287 words, about 1 min05Control
The Control domain sustains the gains and transfers ownership to the process owner. ICGB tests whether you build a control system that detects drift and triggers action.
287 words, about 1 min