Six Sigma is a disciplined and data-oriented method used to eliminate defects in a project process starting from the manufacturing all the way to service. Its intention is to ensure that defects do not exceed 3.4 in millions of opportunities in a project process. The Six Sigma training and certification program covers four levels, namely, Yellow Belt, Green Belt, Black Belt, and Master Black Belt.

The Yellow Belt certification is at the basic level of the Six Sigma program. A Yellow Belt understands the Six Sigma basic concepts and works with teams to solve problems and support projects in an organization. To qualify for the Certified Six Sigma Yellow Belt (CSSYB) certification, an individual is supposed to sit for an open-book exam. The test that is computer delivered has 85 questions, 10 of them are unscored. The student has 2.5 hours to complete them. But the paper and pencil exam contains 75 questions and takes 2 hours. The test costs $394.

The Green Belt certification is awarded to those candidates who have proven their skills in working on complex projects alongside other team members. A Green Belt can also be a project leader on simpler projects. Regarding complex projects, they work with the Black Belts who are project leaders. To qualify, the candidate must sit for an open-book exam. The computer delivered test includes 110 questions, 10 questions are unscored. The exam length is 4.5 hours. The paper and pencil test has 100 questions and 4 hours to answer them. The exam leads to the award of the Certified Six Sigma Green Belt (CSSGB) credential. The test cost is $438.

The Black Belt certification is designed for those who have demonstrated their expertise in leading teams and executing projects successfully while being supervised by a Master Black Belt. A Black Belt member reports to a Master Black Belt member and is required to work full-time. They are involved in preparing project charters, leading project teams, and supervising the Green Belts who are responsible for executing simpler projects. The Certified Six Sigma Black Belt (CSSBB) computer delivered exam is a 4.5-hour test with 165 multiple-choice questions. 150 questions are scored while the other 15 are unscored. The paper and pencil exam contains 150 questions and lasts 4 hours. The fee is $538.

The Master Black Belt certification is targeted at the professionals who have demonstrated that they are capable of leading project teams in successfully executing huge projects. The Master Black Belts report directly to unit managers or senior executives. They act as advisors to the senior executives. To qualify, one must have led at least ten teams to execute huge projects or have an experience of 5 years working as a CSSBB or a MBB. The CMBB exam lasts 5.5 hours and comprises 110 multiple-choice and performance-based questions. 100 questions are scored while the other 10 are unscored. The cost of this test is $2229.

The Six Sigma exams are administered by the American Society for Quality (ASQ) through Prometric testing center. The certifications are valid for three years.