Difference Between Lean and six sigma

Lean and Six Sigma are in no way related. Anyone who thinks they are would benefit from a deeper understanding of lean and some background on six sigma’s origins at Motorola.

The term ‘Lean Sigma’ is an attempt to provide the best of both worlds and rarely produces the cultural changes necessary to support & sustain lean transformation.



SIX SIGMA is a tool used to improve the quality of process outputs by identifying and removing the causes of defects (errors) and minimizing variability.

6sigma programs are generally long duration and focus heavily on statistical methods & measurement;

A six sigma process is one in the products manufactured are statistically expected to be free of defects (3.4 defects per million).

It has its applications;
however the people involved do not necessarily employ a deep understanding of the processes they are improving.

The result is often lack of ownership by the people doing the actual daily work, so changes do not stick.

The “find it - measure it - analyze it - fix it” to save dollars fast approach often leads to point improvements that may even be CONTRARY TO LEAN PRINCIPLES.
- some 6sigma solutions have actually led the organization away from lean and increased total cost



LEAN is a management system, a culture, and a philosophy, focused on providing value to the customer and removing waste.
It requires the engagement of all employments and the transformation of how we manage.
It is NOT just a set of tools, or about workforce reductions and eliminating people.
Lean can be a growth strategy to create new opportunities based on Customer Focus to only provide value.






Most problems people apply 6sigma to can be solved at the root cause using common sense by an empowered front line worker - eliminating the need for any 6sigma statistical analysis.

There may be points in a lean organization where 6sigma can be used.
Organizations should not focus on any one quality improvement tool but on the appropriate tools for each specific problem. Too many company managers embrace popular programs, like SixSigma, ignoring waste reduction and other variability reduction methods that can also provide
huge improvements. Within a targeted area, a blended application of tools will have a much greater impact than focusing on a few select projects.

Lean philosophy focuses on overall system effectiveness; 6sigma focuses on point improvements.

Lean thinking is a way of operating an organization; 6sigma a tool.

There is no Six Sigma in Lean; just like there is no hammer in ___________.
A carpenter may require the use of a hammer if he has the need to strike some thing, however there are many other tasks he is responsible for that require his thinking.