What is Six Sigma?

Six Sigma is a data-driven problem-solving methodology. The focus is on process variations and emphasis is given to customer satisfaction. Continous process improvement with low defects is the goal of this method.

The Origins of Six Sigma

Six Sigma originated with Bill Smith at Motorola in 1986 with help from his colleague Mikel Harry. Together they developed the DMAIC improvement method—Define, Measure, Analyze, Improve and Control—which guides practitioners to systematically define and address the root causes of process problems and then maintain the gains.

The Belt Levels

Six Sigma is synonymous with the martial-arts-based instructional belt levels—Green Belt, Black Belt and Master Black Belt, etc.—that indicate the different roles and abilities of problem solvers. The structure encourages a mix of practitioners with different skill levels to partner with each other as well as with coaches and mentors to guide them.

What Exaclty Does “Six Sigma” Mean?

Six Sigma has three separate but interrelated meanings:

  1. It’s a system of measurement—defining how capable a process is of meeting customer requirements
  2. It’s a goal—reaching “Six Sigma” means producing only 3.4 defects per million opportunities (DPMO)
  3. It’s a method of process improvement—analyzing and solving process problems at the root to achieve outstanding and lasting performance

What does 3.4 defects per million opportunities look like? As pictured, it means near perfection. Considering the scholastic grading system, anything in the 90s guarantees some form of an “A.” But 6 Sigma (3.4 DPMO) requires the process to be 99.99966% defect-free. That’s a much tougher grading system!

Practitioners believe that the people doing the work understand best how to address the root causes of process problems and improve process capability. It’s a project-based method that promotes data-based decision making and “management by fact” as opposed to opinion.

The tools of  Six Sigma?

Six Sigma projects are associated with statistical thinking used to reduce process variation with tools such as Control Charts, Process Maps and Failure Modes & Effects Analysis (FMEA). The effect is to institute rigor into the culture and avoid the types of knee-jerk “problem→solution” thinking that results in increased variation, rework and persistent process issues.

Leadership aligns DMAIC projects to help organizations achieve their corporate strategy and accomplish their missions. Results include defect reduction, increased profits, better employee morale and superior quality products and services.