I’ve long been skeptical of so-called “Lean Sigma” or “Lean Six Sigma.” And not because I’m against Six Sigma statistical methods, which are valid and helpful in solving certain difficult problems.
What I don’t like is the oft-stated “Lean Sigma” mantra that says something like, “Lean and Six Sigma are just tools in the improvement toolbox; so use the right tool for the right problem.”
Lean is far more than process improvement tools.
As Toyota people, like Jamie Bonini, would say today, Lean and the Toyota Production System are an “integrated system” that includes:
- Technical methods
- Managerial approaches
- People development
- Organizational culture
Read more here:
So I stumbled across this image that was shared on LinkedIn by a “Lean Six Sigma Master Black Belt,” a term that would imply they know a lot about both Lean and Six Sigma. Or they know a lot about that Frankenstein of a “Lean Sigma” approach:
He added the text:
“it is a waste of time making things idiot-proof, as the idiots are so ingenious they will still find a way to break it!”
I’m not sure who he was quoting. I don’t endorse either the image or the text.
In the Lean approach, we don’t call people idiots or dummies. We don’t say, or shouldn’t say, things like “idiot proofing” or “dummy proofing.”
There’s an old Toyota story about how the term “fool proofing” upset an employee, they switched to using the equivalent of “mistake proofing” or “error proofing.” Read more about the story in a comment on an old blog post of mine.
Terms like mistake proofing help us focus on the process and the system instead of blaming individuals. Instead of labeling people as idiots, we have to focus on improving the system so it’s easier to do the right thing and harder for errors to occur.
The great book The Checklist Manifesto points out the need to improve systems so smart people (like surgeons) don’t make errors or have a bad day. Surgeons aren’t idiots. Neither are airline pilots and they use checklists and other systems to prevent errors.
Error proofing is NOT a waste of time. Employees aren’t idiots who are looking for ways to cause problems.
We have to be respectful.
There’s a risk that people using “Lean tools” from their “toolbox” don’t understand or practice the philosophy of Lean that says, in part, that people want to do quality work and that we should respect them and work together, as this quote from former Toyota executive Gary Convis says (a quote I often use in training classes and workshops):
“You respect people, you listen to them, you work together. You don’t blame them. Maybe the process was not set up well, so it was easy to make a mistake.”
If that mindset is missing from the “toolbox,” then the use of random Lean tools like 5S shouldn’t really be labeled “Lean.” If there’s an arrogance that creeps into Six Sigma (experts solving problems in complicated ways), then that needs to be kept out of “Lean Sigma.”
Back to the LinkedIn post… an engineer proudly posted this story that made me cringe:
“Something I say way too often. That said, in design and in search of ‘perfection’, and what is Six Sigma if not the search for perfection, I see it as an essential function. Sometimes it requires innovation. For example, I knew that in one plant I designed equipment for, the operators were notorious for tampering with machine settings. As such, I added ‘placebo’ controls to a machine to satisfy their ‘need’ to readjust. At the end, every shift was convinced that their settings worked best. So. in conclusion, sometimes it’s important to blend a little psychology with good engineering, to achieve your goal.”
I posted this response:
“Arguably, what you did there wasn’t innovative, but perhaps rude and disrespectful to those operators. As an engineer, I’d argue you have an obligation to teach them and work together with them, rather than fool them with placebo controls. Which approach is better in the long term?”
Now, the engineer (thankfully) wasn’t labeling what he did as “Lean.” But, he was basically labeling the workers as idiots.
He missed an opportunity to teach the workers about tampering, using lessons from Dr. Deming or his famous “funnel experiment” that shows the impact of overadjustment.
I think an engineer should teach. That’s respectful and, I think, better for the organization in the long term. What do you think?