Blog post

My whole career, I have worked with the Lean methodology (aka the Toyota Production System).

I've just really never done much with Six Sigma. I've read about Six Sigma. I took a Green Belt course when I worked at Dell in the late 90s. I've studied and used statistical methods (especially what I learned in my Industrial Engineering studies and at MIT), but I've never done anything I would call Six Sigma in my career.

I have respect for Six Sigma as a discipline, just as if I were a chef, I would have respect for pastry chefs. They can co-exist in the kitchen. You might both use whisks, but you have slightly different training to do different things. These roles aren't interchangeable, and neither are Lean and Six Sigma. That's one reason I get riled up about so-called “Lean Sigma” or “Lean Six Sigma.”

Most of the “L.A.M.E.” (Lean As Mistakenly Explained) examples that I see on the interwebs come from “Lean Sigma” discussions, especially on LinkedIn.

What are the fallacies that are thrown around? They include, but are not limited to:

• Lean is about the average, Six Sigma is about the variation
• Lean is about internal processes, Six Sigma is customer-focused
• Lean is for efficiency; you need Six Sigma for quality (this one is the fault of Mike George and his books, many say)
• Lean and Six Sigma are just toolboxes, and you use whichever is appropriate for the problem at hand

These are all incorrect, as somebody with good Lean training or Lean experience would realize.