Preparing for certification
Whichever certification you aim for, the practice is the same
Lean Six Sigma certification bodies differ in the duration of their exam, their pass mark, their language and their price. They hardly differ in what they ask you to know: it is the same DMAIC body of knowledge, the same Lean tools, the same introductory statistics. Revising for one is revising for the others.
beltup trains for that common foundation: marked quizzes with no sign-up, a glossary of every tool, and tracks by level. The Yellow Belt level is fully open, with no account and no bank card.
What remains is choosing the exam. There is no single official body: no public authority holds the title, and several private institutions each award their own. The table below says what sets them apart — without singling one out.
The four bodies below are not “the main ones”: they are those that award a Green Belt certification by exam, internationally, and that publish their exam conditions. Others certify — that is the criterion, not a ranking. The French route, which does not work by exam, is covered further down.
The conditions below were read on the bodies’ own pages on 31 August 2026. Each row carries its source link. beltup awards none of these certifications and is not affiliated with any of these bodies: that is what allows it to present them side by side.
What sets the exams apart
| Body | Questions | Duration | Pass mark | Materials | Validity | Price | In French |
|---|---|---|---|---|---|---|---|
| IASSC | 100 | 3 h | 70 % | closed book | recognised without limit, but “current” for three years | 350 $ | no |
| CSSC | 100 | 2 h | 70 % | open book | no expiry date | 195 $ | no |
| ILSSI | 100 | 2 h | 70 % | closed book | not published | 216 £ | yes |
| ASQ | 100 | 4 h 18 | not published | open book | not published on the pages consulted | not published | no |
Green Belt exam conditions. Prices are for the exam alone, in the currency displayed by each body, excluding training.
What these differences change when you revise
IASSCInternational Association for Six Sigma Certification · United States
Closed book and three hours for a hundred questions: it is the exam where memorisation counts most, and the one best prepared with timed series. The 70 % mark leaves room for thirty mistakes.
Conditions published by IASSCCSSCCouncil for Six Sigma Certification · United States
Open book, but only two hours: looking up every answer in your notes does not keep pace. The documentation serves for formulas, not for reasoning.
280 points out of 400.
Conditions published by CSSCILSSIInternational Lean Six Sigma Institute · United Kingdom
The only one of the four to offer the exam in French. For someone who learned the vocabulary in French, that removes a difficulty that has nothing to do with Lean Six Sigma.
Conditions published by ILSSIASQAmerican Society for Quality · United States
Four hours and eighteen minutes, open book: it is the longest exam, and the one where documentation really helps. On the other hand, the absence of a published pass mark prevents setting a numerical target for practice.
ASQ does not publish a pass mark as a percentage: the score is scaled, and the bar varies with the version of the exam.
Conditions published by ASQAnd in France: the registered route
The four exams above are sat in English — except ILSSI’s — and require no project: you register, answer a hundred questions, obtain a title. The French route is of a different nature. A certification listed in France Compétences’ Répertoire Spécifique is assessed on a file, and it is that one that can be funded through the French personal training account (CPF).
Pilotage d’un projet d’amélioration de la performance — niveau Green Belt
RS7428 · certifying bodies: UL6S, CESI · registration valid until 27 November 2030
Assessment: written exam and technical file based on case studies. So it is not a multiple-choice test that decides, but written work on cases — practising questions prepares the foundation, not the file.
France Compétences recordBeware of references still in circulation: record RS2257, still cited on many sites, has been inactive since 31 December 2021.
What this table does not say
It does not say which one to choose. Recognition of a body depends on your sector, your country and often your employer: that is who to ask before paying a registration fee. A title that is not recognised where you work is not worth its price, whatever the exam conditions.
Nor does it say anything about the expected content, which varies little from one body to the next: it is the same DMAIC body of knowledge, the same Lean tools, the same introductory statistics. That is precisely why practice helps whichever body you choose.
What the table changes for your preparation
Three of the four exams require 70 % on a hundred multiple-choice questions. That is a target you can measure: the free Green Belt quiz gives a first benchmark in ten minutes, with no account and no bank card. The Yellow Belt level is fully open.
Then there is pace, which only a timed exam reveals. A hundred questions in two or three hours leave a little over a minute per question: that is exam mode — a timer, marking withheld until the result — which has to have been practised before, not on the day.
And if you aim for the French route, the foundation will not be enough: a case-study file is prepared differently from a multiple-choice test. Practising questions gives you the tools and the vocabulary; the file, for its part, requires a real project.
Do you train people in Lean Six Sigma?
This page compares certification bodies, not training providers: preparing for a certification and awarding it are two different trades, and beltup practises neither. It equips the first — composing assessments, following learners, results reports — and stays clear of the second.
What beltup offers training providersbeltup is an independent practice tool. It awards no certification and is not affiliated with any of the bodies named, whose names and acronyms belong to their respective owners. The conditions shown are those published by each body on the date indicated; they may change without notice, and only the body’s own page is authoritative.