ICGB Body of Knowledge (BOK)

The IASSC Certified Lean Six Sigma Green Belt (ICGB) certification validates a professional’s competence in applying Lean Six Sigma methodologies, tools, and practices to improve processes and reduce defects within an organization. Achieving this credential signifies a deep understanding of problem-solving techniques and a commitment to operational excellence. Many aspiring Green Belts approach the ICGB exam with traditional study methods, often finding themselves unprepared for the nuanced application of concepts required. This article delves into the inherent shortcomings of conventional preparation and outlines an expert blueprint designed for authentic mastery and successful certification, distinguishing itself from typical study guides by emphasizing a strategic, holistic approach.

Updated on 29 September 2026. What’s new: iassc lists the green belt exam at usd $350 and needs no work experience to sit it or to hold the certificate

The ICGB is the IASSC Certified Lean Six Sigma Green Belt exam: 100 closed-book questions in 180 minutes, a 70% pass mark and a USD $350 fee, with no prerequisites to sit it. About 20 questions come from each of five sections, Define, Measure, Analyze, Improve and Control, so no phase can be skipped. This guide sets out the paper, the topics inside every section, how to choose the right hypothesis test and a six-week study plan.

People searching for the ICGB meaning are usually asking two things at once. The letters stand for the IASSC Certified Lean Six Sigma Green Belt, and IASSC is the International Association for Six Sigma Certification, an independent body that certifies knowledge rather than training. It does not run courses. It sets a Body of Knowledge, writes the exam and issues the certificate, which is why the same exam can be reached after a classroom course, a company programme or plain self-study.