Hat tip to Kevin Meyer for sending me a link to this ridiculous post from the website of Minitab, the maker of statistical software that’s used by Six Sigma belts: “Lean, Six Sigma, or Lean Six Sigma?“ I’m sure my comment there won’t be published, so I’ll share my thoughts here.
There’s often a lot of misinformation spread about Lean, often by those who got just a smidge of Lean training during their green belt or black belt classes. It’s one thing to have a different opinion… it’s another to be factually wrong.
The blog post starts off on an odd note:
Some companies call their quality programs “process excellence initiatives” or “continuous quality improvement,” while others refer to their programs as “Lean” or “Lean Six Sigma.” Others subtract ‘lean’ from their program titles altogether, and refer to their efforts simply as “Six Sigma.”
Lean and Six Sigma are distinct, yet related, methodologies. The terms, along with Lean Sigma or Lean Six Sigma, are not just synonyms or alternate terms for the same thing. Lean is essentially the Toyota Production System. Six Sigma comes from Motorola and G.E. There are some shared roots in Total Quality Management, perhaps. They can be used together, but Lean and Six Sigma are not the same.
Toyota doesn’t use formal Six Sigma, as they primarily use just the seven basic Q.C. tools, without the formality of belts (I’ve heard this first-hand from Toyota people at their plants).
The post asks:
Are there really any differences, or is all of this terminology just jargon for ‘process improvement?’
Yes, there are differences. Not, it’s not just interchangeable jargon.
The short answer to that question is that it all means process improvement, but there are some key differences to be aware of.
No, it’s not just different terms for P.I. Yes, there are some key differences. For one, I think Lean is more of a holistic management approach, as opposed to an improvement methodology (Six Sigma). Lean is more inclusive and allows everybody to participate in improvement, while Six Sigma is expert-driven (the belts). Lean uses what many would use “common sense” improvements (although that’s a loaded term), while Six Sigma uses more complex methods that generally wouldn’t be included in Lean (but could be used in a Lean culture).
The post is then actually OK for a bit:
Both methodologies seek to make processes and the business as a whole more efficient by removing defects or waste through focused efforts that likely involve a project-based approach.
I can’t disagree with that. The statement is more correct than the commonly-used falsehood of “Lean is for efficiency and Six Sigma is for quality.”
Then, it gets weird again.
However, Lean refers to activities that are meant to be quick and efficient while Six Sigma projects are meant to be thorough and permanent.
Sigh, Lean improvements are not thorough or permanent? That’s wrong.
SIPOC is primarily a Six Sigma thing. I wouldn’t call that a “Lean tool.” FMEA is a method that predates both Lean and Six Sigma and I’ve certainly used FMEA in the context of Lean work.
Regardless of what you call your quality improvement endeavor, keep an open mind and rely on data analysis to drive improvements. Personally, I think Lean and Six Sigma are like peanut butter and jelly, or even Laverne and Shirley. You certainly can’t have one without the other!
I agree we should have an open mind and that there’s a place for the complex statistical analysis of Six Sigma.
You certainly CAN have one (Lean) without the other (Six Sigma).
As I’ve said before — I’m not opposed to Six Sigma. I’m opposed to Six Sigma people spreading misinformation about Lean. Minitab should stick to blog posts about statistics or Six Sigma.
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