ICBB
IASSC Certified Lean Six Sigma Black Belt Exam
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ExploreAbout this exam
The IASSC Certified Lean Six Sigma Black Belt (ICBB) is a third-party professional designation for practitioners who are well versed in the Lean Six Sigma methodology and who lead complex improvement projects, typically in a full-time capacity. The credential signals advanced proficiency across the DMAIC phases - Define, Measure, Analyze, Improve and Control - as defined by the IASSC Lean Six Sigma Black Belt Body of Knowledge. It suits experienced improvement leaders, program managers and full-time project leaders rather than occasional project participants. The exam is a closed-book, proctored test with a four-hour allotted time, delivered at testing centers worldwide, through online proctoring, and via accredited providers. It draws roughly 30 questions from each major Body of Knowledge section, mixing multiple choice and true/false, and some forms may add up to 15 non-graded questions. There are no prerequisites to sit, but IASSC recommends training through a qualified institution, trainer or corporate program, plus some real-world Lean Six Sigma project experience. A non-proctored evaluation exam is available to gauge readiness. Certification is recognized perpetually, with "Current" status governed by the recertification policy.
What you'll study
About ICBB preparation
What exactly is the ICBB credential?
It is the IASSC Certified Lean Six Sigma Black Belt designation, issued by the International Association for Six Sigma Certification as an independent third-party certification. It recognizes a professional who understands and can apply Lean Six Sigma at an advanced level and who leads complex improvement projects, usually full-time, across Define, Measure, Analyze, Improve and Control.
Do I need prerequisites or a prior belt to sit the exam?
No. IASSC states there are no prerequisites required in order to sit for the Black Belt exam. Training through a qualified institution, trainer or corporate program is recommended but not required, and some degree of real-world Lean Six Sigma work and project application experience is also recommended rather than mandated.
What is the exam format and how long does it take?
It is a 150-question, closed-book, proctored exam with a four-hour allotted time. It contains approximately 30 multiple-choice and true/false questions from each major Body of Knowledge section. Some exam forms may include up to 15 additional non-graded questions, so do not assume every item you see counts toward your score.
What score do I need to pass?
Candidates must achieve a minimum score of 70% on the IASSC Certified Lean Six Sigma Black Belt Exam to earn the IASSC Certified Black Belt designation. Plan your pacing around that threshold: with 150 questions in four hours you average roughly 1.6 minutes per question, so flag and return to lengthy calculation items.
Where and how is the exam administered?
IASSC administers the exam in more than 8,000 testing centers located within 165 countries, through the PeopleCert online proctoring system, and through hundreds of IASSC Accredited Providers. Vouchers can be purchased for on-demand web-based delivery or as an IASSC-PearsonVue exam, depending on the route you choose.
How much does the exam cost?
A Black Belt Exam Voucher is purchased for $450 USD. Check the current purchase page before budgeting, since pricing and delivery options are set by IASSC and can change. Training through an accredited provider, if you choose it, is a separate cost that is not included in the exam voucher price.
How should I sequence my study across DMAIC?
Work through Define, Measure, Analyze, Improve and Control in order, because each phase supplies tools the next one assumes. Give extra time to Measure and Analyze, where statistics and hypothesis testing dominate, and to Improve for design of experiments. Finish with Control, covering control plans, SPC and mistake-proofing, then take a timed practice run.
Is there a way to check readiness before paying for the real exam?
Yes. IASSC offers a non-proctored, informal Black Belt Evaluation Exam that may help you determine whether you are ready to sit for an official proctored certification exam. Treat it as a diagnostic: review every missed item against the Body of Knowledge before booking the proctored test, since the evaluation is not itself a certification.
How long does the certification stay valid?
IASSC certification is recognized perpetually, but under the IASSC Recertification Policy effective March 1, 2017, a classification system recognizes certifications as "Current" for a period of three years and defines regulations for maintaining that status. Successful candidates receive a certificate with a certification number, a badge, and register listing.
What are the most common ways candidates fail?
Typical failure modes are memorizing definitions without being able to interpret output, skipping statistical depth in Measure and Analyze, and running out of time on calculation-heavy items. Others underestimate Control tools or never simulate the closed-book, four-hour, proctored conditions. Practicing under timed, no-reference conditions exposes these gaps before exam day.