What Is Lean Six Sigma Anyway?
©2020, George J. Irwin. All rights reserved.

If I’m going to provide some tales, tips, and thoughts about Lean Six Sigma, it makes sense to start off with an Operational Definition of that term. (And by the way, “Operational Definition” is a Lean Six Sigma-appropriate term.)


The basic idea behind Lean Six Sigma is Process Improvement. This could be a physical or other process: making widgets, fixing widgets, or reporting on widgets. It got its start in manufacturing but has since expanded to service industries. I’ll resist the temptation to provide the textbook explanation of how six sigma is an important concept—that can be found in lots of places online and in books—but suffice to say that the idea is to get a process as well-functioning as makes practical sense. And in some cases, that means blowing right past Six to Seven, Eight, and Nine Sigma.

There are two pieces to Lean Six Sigma, and when done right, they complement each other. Very simply put, the “Lean” part is reducing waste in a process and the “Six Sigma” part is reducing variation in a process.

It’s possible but not really optimal to do one without the other. For example, you could be really quick and efficient at making donuts that are round, square, triangular or octagonal when the customer only wants round donuts—that could use some Six Sigma work. On the other hand, you could make perfectly round donuts every time but it takes five hours each and you throw out half the mix at the end of the day—that needs a Lean intervention.

There exist an abdundant number of tools available for Lean Six Sigma projects, and contrary to what you might have read or heard, they do not all need a degree in Statistics to use properly. In fact, many of them just require a little instruction and coaching and a little discipline. Though it seems I may blaspheme here, sometimes the full strength version of a tool is not required to make progress. A favorite phrase used by instructors in the classes I took was, “It depends,” and that’s much more true than it isn’t.

The benefits of Lean Six Sigma converge on better output, lower effort and cost, and more satisfaction, on the part of both customers and process participants. To be fair, though, the most common complaints about Lean Six Sigma is that it takes too long, requires too much effort, is too technical, and doesn’t deliver the benefits it promises. All of those objections can be overruled, although the key is carefully selecting a process to address in the first place.

In following posts, I’ll take you through my experiences with Lean Six Sigma, as both a practicioner and a customer. I hope you’ll find that even if you never find yourself on a project team, you’ll capture a few useful takeaways.

More from the Notebook...