Six Sigma Certification – ASQ® or IASSC?

Many of my Six Sigma Green Belt and Six Sigma Black Belt students have asked me these questions:

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  • Which certification should I go for ASQ(American Society for Quality) or IASSC (International Association for Six Sigma Certifications)?
  • Which of these to certificates is most valued - ASQ or IASSC?

Let's understand a few key facts before I talk about these two certifications.

1. ​There is no global central accreditation agency for Six Sigma certifications. Numerous bodies offer Six Sigma certifications. For that matter, anyone can issue a Six Sigma certification.

Because of this fact:

  • ​a) you should spend money on only those certifications which are globally recognized by employers.
  • b) Your focus should be on getting the knowledge, rather than the certificate.

2. ​There is nothing better than attending the in-house Six Sigma training provided by your organization supported by completing a project. In-house courses will give you the best experience and knowledge. However, this does not work ​for many people, who want to upgrade their knowledge and learn Six Sigma concepts, when the organization is not interested in formally implementing the Six Sigma program.

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Six Sigma Black Belt  (SALE)

Certified Six Sigma Black Belt Course in Plain and Simple Language - ASQ CSSBB Exam Preparation Online Course


Let's quickly look at the similarities and difference between these two certifications.

Both of these certificates are well recognized globally. As far as my personal opinion is concerned, I am inclined more towards ASQ certification. I prefer ASQ certification, and hence ​ I have personally gone for ASQ CSSGB and CSSBB certifications.

Body of Knowledge:

​The Define, Measure, Analyze, Improve and Control (DMAIC) components of the ASQ and IASSC ​Bodies of Knowledge are almost identical. However there are some additional knowledge requirements in the ASQ Body of Knowledge.


IASSC exam is a closed book exam, while the ASQ exam is an open book exam. This means for IASSC exam you will need to memorize a lot. In case of the ASQ exam, your emphasis should be understanding the concepts rather than memorizing. 

Green Belt:

IASSC ​Certified Lean Six Sigma ​Green Belt

Three years of work experience in one or more areas of the Six Sigma Green Belt Body of Knowledge.

​No prerequisite

Cost of Exam:
ASQ ​Certified ​Six Sigma ​Green Belt
​IASSC ​Certified Lean Six Sigma ​Green Belt

​ASQ Members: $​338 USD

Non members: $​438 USD

​$295 USD

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Six Sigma Green Belt  (SALE)

Fully aligned with ASQ Certified Six Sigma Green Belt (CSSGB) Body of Knowledge. Includes Minitab 18 examples.

​Black Belt:

A significant factor in choosing between ASQ and IASSC certification is whether you have completed a Six Sigma ​project in the past or not. ASQ needs you to provide one or two project completion affidavits signed off by your supervisor confirming that you have completed Six Sigma project in the past.

There is no project completion requirement for IASSC certification.

ASQ ​Certified ​Six Sigma Black Belt
​IASSC ​Certified Lean Six Sigma Black Belt

​​Two completed projects with signed affidavits 


One completed project with signed affidavit and three years of work experience in one or more areas of the Six Sigma Body of Knowledge.

​No prerequisites

Cost of Exam:
ASQ ​Certified ​Six Sigma Black Belt
IASSC ​Certified Lean Six Sigma Black Belt

​ASQ Members: $438 USD

Non members: $538 USD

​$395 USD

Six Sigma Black Belt

  • Course based on ASQ CSSBB Body of Knowledge.

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