Lean Six Sigma

Learn how to introduce, apply & adapt Lean Six Sigma within an organisation

Lean Six Sigma

Lean Six Sigma is the most popular business performance methodology in the history of corporate development.

The Lean Six Sigma (LSS) certifications are designed to support corporate in their mission to improve customer satisfaction, boost performance levels, and shorten the time-to-market. Self-employed professionals and consultants are looking to benefit from the above-average salary level provided by Lean Six Sigma certification and its potential for cross-industry application.

Lean focuses on efficiency through the minimization of waste, errors, and delays, while Six Sigma focuses on quality and consistency through processes improvement and variation reduction. The combination guarantees cost and time efficient products and services of the highest quality.

Lean Six Sigma is made of three levels, or ‘belts’, that provide a complete array of techniques for optimising production processes, cost efficiency, and product quality.


Lean Six Sigma Certification Scheme


Lean Six Sigma Yellow Belt 
Elementary knowledge of the LSS Method and performing tasks


Lean Six Sigma Green Belt
Intermediate understanding of the LSS Method and some experience working in more complex projects


Lean Six Sigma Black Belt 
Thorough understanding of the LSS Method and ability to successfully lead complex improvement projects


Holders of all Lean Six Sigma - IASSC® Certified Belts are required to be re-certified within 3 years from their original certification.


Lean Six Sigma Frequently Asked Questions

Lean Six Sigma Frequently Asked Questions

Which exams do not need to go through a training provider and allow me to self-study?

The Lean Six Sigma exams require no pre-requisites, no specific training and no proof of project work, although training with an Accredited Training Organisation for the Black Belt exam is highly recommended.

How long does the exam take?

Exam times vary depending on the level. Please check each level separately for a quick overview of each exam.

Are the exam questions multiple choice, essay style or both?

All questions are multiple choice.

Are the exams Open Book?

No. IASSC provides a Reference Document in either paper or electronic form, subject to which form of exam one is taking. This document contains all formulas and tables one will need during the examination. Scratch paper is included in this document and must be discarded or returned to the Proctor before the candidate leaves the Testing Centre. If taking a paper based exam one may bring an arithmetic only calculator into the Testing Center.

When will I receive the mark from my exam?

Results are sent within 2 business days upon receipt of the exam papers.

Why has IASSC elected not to have project experience a part of their Certification requirements?

The Certification Board of Directors made a sincere effort to create a viable “application ability assessment”; or, what is commonly referred to in the industry as a “project requirement”.

The issues for project acceptability were: defining “minimum qualifying tools application”, minimum key metric improvement, minimum standards for improvement sustenance as well as a number of other metrics applicable to a Lean Six Sigma project. A method of validating compliance with each key metric could not be established. Therefore, as is foundational to Six Sigma, if the Measurement System cannot be established to an acceptable degree of accuracy and precision, then nothing of value can be said about the issue.

In addition to these concerns were the potential, and likely, proprietary nature of the information contained in a LSS project and the sponsoring firm’s reluctance to allow such projects to be submitted in a format whereby their substance could be assessed. While acceptance of a Project Summary or a Project Affidavit were considered, it was concluded there is no viable means of assuring the validity of such a submittal therefore IASSC could make no definitive statement as to the candidate’s competency based on such a submittal.

With all these issues considered, the Board decided IASSC, and anyone else for that matter, is capable of commenting solely on one’s knowledge relative to the LSSBOK™ and not on their ability to apply such knowledge. That will have to be assessed through other mechanisms.

What is the Universally Accepted Lean Six Sigma Body of Knowledge™?

The ILSSBOK is a document, developed by the industry and organized by IASSC, that defines the knowledge requirements of a Lean Six Sigma exam.

The ILSSBOK is continually updated to ensure that it maintains an accurate alignment with industry standards.

Why are there no pre-requisites to sit for the Certification exams?

The sole objective of the exams is to measure knowledge not work or project experience.

IASSC Certification Exams are developed to assess a person’s knowledge as it relates to the subjects defined in the ILSSBOK. While things such as work experience and application experience are helpful in obtaining the knowledge required to successfully complete the exams, they are not requirements.

Do I get a discount for examination retakes?

No.Retakes are priced at the stated fees, as decided by IASSC.

How many times can I retake the ICBB, ICGB or ICYB exam?

There is no limitation or time restriction on examination retakes.

How many correct answers are needed to pass the exam?

Candidates need a 70% score to pass the exam (questions are marked based on a difficulty level of 1-3).

In what language are the exams available?

All exams are available in English. IASSC Certified Green Belt exams are also available in French.