Consulting Q&ACategory: Consulting ToolkitWhat is the main difference between 6 sigma and lean?
Mikel StasiukMikel Stasiuk asked 8 months ago

1 Answers
Laurent ThomasLaurent Thomas answered 8 months ago
Talking about Six Sigma and Lean works in the same direction: Eliminating waste and creating efficient workflow. They are both methodologies used by Operations Excellence Consultants.

But, there is a difference between them: From a theoretical perspective, one major difference between Lean and Six Sigma is how practitioners of these methods identify waste: In Lean, waste is defined as any process or activity that does not add value to the customer. In Six Sigma, waste results from variation within a process.

Six Sigma focuses on achieving a consistent result by simplifying the process and improving its output with the help of a problem-solving approach based on statistical metrics. At the same time, Lean relies on a collaborative team effort to improve speed and performance by systematically removing process defects and waste and providing a framework for overall organizational culture change in mind.

Both methodologies can coexist in an organization. Lean provides stability and repeatability in many essential processes. Once the process is stable, many variations due to human handling go away. The output collected to support six sigma activities becomes much more reliable and accurate.

The organizations can use lean tools for:

  1. Simplifying processes
  2. To Increase speeds
  3. Improves flow
  4. Minimizes inventories
  5. Create mistake-proof processes


Whereas, Six Sigma tools can be used for:


  1. Minimize variation
  2. Apply scientific problem solving
  3. Utilize robust project chartering
  4. Focus on quality issues
  5. Employ technical methodologies