Six Sigma vs Lean Six Sigma

What is the difference between “Six Sigma” & “Lean Six Sigma”?

“Lean Six Sigma” simply means a program that includes “lean” principles in the Six Sigma Curriculum.

However, with that being said, it is important to realize that essentially all quality Six Sigma programs already have “Lean” principles incorporated into their curriculum.  Therefore, most (if not all) “Six Sigma” programs are actually identical to their “Lean Six Sigma” counterparts.

In a nutshell, in today’s world “Six Sigma” and “Lean Six Sigma” essentially mean exactly the same thing.

The primary reason for the widespread confusion over the naming convention is because although Six Sigma began decades ago, it was only when the military began implementing it that it became a household name. However, since the military often referred to it as “Lean Six Sigma”, the full name became popular… causing mass confusion ever since.

However, to accommodate employers and employees alike, we offer both varieties.

If you are unsure of which to choose, we typically recommend “Six Sigma” for most people. We recommend “Lean Six Sigma” for those that work in the public sector or armed forces.


Originally developed by Bill Smith at Motorola in 1986, the Six Sigma Training program was created using some of the most innovative quality improvement methods from the preceding six decades. The term "Six Sigma" is derived from a field of statistics known as process capability. The term 6 Sigma refers to the ability of manufacturing processes to produce a very high proportion of output within specification. Processes that operate with "six sigma quality" over the short term are assumed to produce long-term defect levels below 3.4 defects per million opportunities. Six Sigma's goal is to improve overall processes to that level of quality or better.