How to Pass the Six Sigma Green Belt Exam
How to pass the ASQ Certified Six Sigma Green Belt (CSSGB) exam: the official Body of Knowledge question counts, 110-question open-book format, the 550 out of 750 cut score, and a DMAIC-based study plan.
Problem this solves
This guide solves the next-step problem for Six Sigma candidates: it explains what matters, then gives you a direct way to test that knowledge with practice questions instead of guessing what to study next.
The Short Answer
To pass the ASQ Certified Six Sigma Green Belt (CSSGB) exam, study the 2022 Body of Knowledge in proportion to its question counts, practise the statistics until the calculations are routine, and build a tabbed, bound reference for the open-book exam. You need 550 of 750 points across 100 scored questions.
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First, Know Which Green Belt You Are Taking
Six Sigma is not one exam. Several bodies certify Green Belts, and their formats differ. This guide covers ASQ's CSSGB, which is the exam our Six Sigma exam prep page summarises. If your employer asked for IASSC's Certified Lean Six Sigma Green Belt instead, the format is different: IASSC lists 100 questions (some forms add up to 10 ungraded ones) in 3 hours, closed book, with a 70% passing mark. The DMAIC content overlaps heavily, but check your certifier's own handbook for the rules that apply to you. ASQ also has an eligibility requirement: three years of full-time, paid on-the-job experience in one or more areas of the CSSGB Body of Knowledge, with no education waivers. Confirm you qualify before you build a study schedule around a test date.
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What the Exam Covers: the 2022 Body of Knowledge
ASQ's 2022 CSSGB Body of Knowledge lists the number of scored questions for each part: - I. Overview: Six Sigma and the Organization (11 questions): value of six sigma, organizational goals and metrics, lean concepts, value-stream mapping, DFSS road maps (DMADV, IDOV) and basic FMEA. - II. Define Phase (20 questions): project selection, SIPOC, voice of the customer (QFD, CTQ trees, Kano), project charters and scope, planning tools (WBS, Gantt, CPM, PERT), management and planning tools, process performance metrics (DPU, RTY, COPQ, DPMO, sigma levels), and team dynamics and roles. - III. Measure Phase (20 questions): process mapping, basic probability, the central limit theorem, statistical distributions, data types and sampling, descriptive statistics, measurement system analysis and process capability. - IV. Analyze Phase (18 questions): multi-vari studies, correlation and linear regression, hypothesis tests for means, variances and proportions, gap analysis and root cause analysis. - V. Improve Phase (16 questions): design of experiments, implementation planning and pilots, and lean tools such as waste elimination, cycle-time reduction and kaizen. - VI. Control Phase (15 questions): statistical process control, rational subgrouping and control charts, control plans, document control, training plans, audits, PDCA, TPM and visual factory. That adds up to 100 scored questions. Define and Measure together are 40 of them, so project basics and measurement deserve as much attention as the statistics people tend to fear. Each topic in the BoK ends with a cognitive level such as Understand, Apply or Analyze; topics marked Apply or Analyze are where you should expect calculation and interpretation rather than definitions.
Format and Scoring
From ASQ's CSSGB certification page and exam-results FAQ: - 110 questions: 100 scored and 10 unscored. You will not know which are unscored. - 4 hours 18 minutes of exam time inside a 4.5-hour appointment. - Open book. You may bring your own bound reference materials. - Computer-based at Prometric, with paper-based delivery in some locations. - To certify you need 550 points out of a possible 750. - Fees listed by ASQ: $483 for non-members, with a $100 member discount, and $283 for a retake. Because the score is reported on a 750-point scale, do not try to convert 550 into a fixed number of correct answers. Study to understand the whole Body of Knowledge, not to a target count.
A Practical Study Plan
1. Map the BoK to a calendar. Give each of the six parts study time in proportion to its question count, and put the statistics-heavy Measure and Analyze parts in the middle, once the vocabulary from Overview and Define is in place. 2. Learn each DMAIC phase as a sequence of decisions. For every phase, write down the question the team is trying to answer, the tools that answer it, and the output that moves the project to the next phase. Many questions are scenarios that ask which tool comes next. 3. Make the calculations automatic. Practise DPMO, RTY, sigma level, Cp and Cpk, control limits, basic probability and hypothesis-test decisions by hand with your exam calculator until you no longer need to think about the steps. Open book helps you look up a formula; it does not give you time to learn one. 4. Build your reference early. Choose one primary text, tab it by BoK part, and add a single summary sheet per phase with formulas and tool-selection rules. Use only the reference you will take into the exam when doing practice sets, so you know where everything is. 5. Practise timed sets. 110 questions in 4 hours 18 minutes is a little over two minutes each. Use a question bank in timed blocks, then review every miss against the BoK topic it came from. 6. Use the last week for review, not new material. Re-read your phase summaries, redo the calculations you missed, and take one full-length timed practice exam.
Mistakes to Avoid
- Assuming open book means less study. Looking up every answer is the fastest way to run out of time. - Bringing an untabbed or unfamiliar book. Your reference only helps if you can find a table in under a minute. - Studying the statistics and skipping Define. Part II alone is 20 scored questions on charters, VOC, teams and project tools. - Mixing certifiers. IASSC and ASQ have different formats and rules; use the right handbook. - Memorising formulas without interpretation. Know what a Cpk below 1 or an out-of-control point actually means for the process.
Exam-Day Tips
- Check ASQ's and Prometric's current rules for permitted reference materials and calculators before test day; do not assume. - Arrive early with the identification Prometric requires. - Answer the questions you know first, flag the ones that need your book, and come back to them. Never leave a question blank. - For calculation questions, write down what is being asked before you start, and sanity-check the result: a probability above 1 or a negative standard deviation means a slip. - Watch the clock at the halfway point. You should be past question 55 with time left for flagged items.
Keep Practising
Drill by DMAIC phase with the Six Sigma exam prep question bank, and check your starting point with the free Six Sigma practice test. Practice percentages are not converted into ASQ's 750-point scale; use them to find weak areas.
Sources
Checked 2026-10-16. - ASQ — Six Sigma Green Belt Certification (CSSGB) - ASQ — 2022 Certified Six Sigma Green Belt Body of Knowledge (PDF) - ASQ — Exam results FAQ - IASSC — Certified Lean Six Sigma Green Belt
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