I always get annoyed when people spread the false dichotomy of “Lean is about efficiency and Six Sigma is for quality.” Replace the word “efficiency” with “speed” or “flow” and it's still wrong.
Here is an example of this falsehood in a book from a major publisher… this author refers to Lean addressing the first six types of waste, with Six Sigma addressing the waste of Defects. Ugh. Wrong.
The author repeats this falsehood in different ways throughout the book. The book also incorrectly states that Virginia Mason Medical Center used Lean/TPS *and* Six Sigma.
At least the VMMC CEO Dr. Gary Kaplan learned correctly that Lean (coming from Toyota) is about Cost AND Quality, as we'll read about below.
Here is a recent piece by Dr. Kaplan:
The pathway to higher quality and lower costs is the same
While he doesn't share specific data, Kaplan ends the piece with:
“We are achieving the seemingly contradictory outcomes of lower costs and higher quality.
All of us in healthcare have a moral imperative to make care better, faster and more affordable. Using the tools of the Virginia Mason Production System, we are finding that the pathway to higher quality and lower costs is the same.”
The Journal of the American Medical Association (JAMA) recently published an article that shows a correlation between Lean management practices and lower cardiac mortality rates.
Management Practices and the Quality of Care in Cardiac Units
Researchers from OHSU (in Oregon) studied 600 units and found only 20% had best practice management practices (based on manufacturing, namely Lean/TPS) and those units had lower (better) mortality.
Leading organizations had a formal method for continuous improvement (or “kaizen“), with those scoring highest having a system where they:
“Exposing problems in a structured way is integral to individuals' responsibilities and resolution involves all staff groups, along the entire patient pathway; exposing and resolving problems is a part of a regular business process rather than being the result of extraordinary efforts.”
As Dr. Atul Gawande tweeted:
Update: Gawande was INCORRECT. It was only a 0.17% lower rate. Shame on me for not confirming that, but I didn't have access to the whole article.
The article concluded:
“Conclusions and Relevance The use of management practices adopted from manufacturing sectors is associated with higher process-of-care measures and lower 30-day AMI mortality. Given the wide differences in management practices across hospitals, dissemination of these practices may be beneficial in achieving high-quality outcomes.”
If you don't have access to JAMA through your organization, you can read the OHSU press release here.
Six Sigma CAN help. But it's certainly not necessary for improving healthcare quality.
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As someone who started off learning Six Sigma and then separately lean; I am a little sensitive so bear with me;
What is the appropriate dichotomy? Why the denigrating of six sigma?
The belt colors are goofy sure, but I’d say it using Japanese terms as though they were wisdom themselves is every bit as goofy.
I agree the above definition does no one any justice. And the people who peddle those kinds of half truths do more harm than good for everyone in the improvement industry.
Just like there is LAME; its unfortunate that perhaps some of the most marque six sigma companies are more sick sigma than anything else (GE’s Six Sigma is nothing like what I learned) but that doesn’t mean the methods are in and of themselves bad or there is nothing to learn from it.
Hi Eric – I haven’t denigrated Six Sigma one bit. I have respect for the statistical methods and scientific rigor of the methodology.
What I’m frustrated with is so called “Lean Sigma.” Stephen Parry calls it, “the worst of both worlds,” and I’ll credit Chad Walters (of leanblitz.net) for calling “Lean Sigma” the “spork” of the process improvement world (not good at being a fork or a spoon).
“Lean Sigma” too often seems to be real Six Sigma with superficial Lean. Six Sigma + 5S + Value Stream Maps isn’t anything close to real Lean.
I can appreciate that there’s “SSAME” (equivalent to LAME) – for example, GE and their cost-driven rank-and-yank culture.
My point is that the half truths (I’d call them falsehoods) don’t serve anybody well.
I think the better dichotomy is that Lean is a management philosophy with methods that can be used by all to solve relatively simple problems while Six Sigma is a problem solving approach that has a small number of experts solving really sticky and complicated problems.
I should have put this in the main post, but I asked Gary Kaplan once if VMMC used Six Sigma and I got a definitive “no” from him. The “Lean Sigma” crowd can’t go taking credit for things done using the Lean/TPS approach.
I did imagine slights that weren’t really there -I’m sorry.
Spork is a great metaphor. But taking it further; there is a time and place for a spoon and a fork. It seems that most people have really only experience in using only spoons and hate forks or forks and dismiss the spoon only crowd. It would be great to hear the spoon crowd acknowledge that while spoons are for everyone, every day there are times when a fork can do the job.
I’ve been in situations where people on the shopfloor were struggling through a 5 why’s problem solving session with what I saw in about two minutes as a measurement system problem. And conversely, early in my career I developed a wiz bang regression model to optimize a product that was essentially made by hand.
So while I am agreed lean sigma misses the mark, there is something to be said for people who’ve decided to make a career of improvement to have a more balanced education. You might major in Lean but having to take some six sigma classes isn’t a bad thing or detracts from being a lean person.
Yes, I’m a “spoon” person who respects the need for forks. We’re in agreement.
great article and something we have been trying to articulate to our prospective clients for about 10 years. i’m glad to see jama on this from this prospective. nothing better to help our 10 years of data than a medical journal to discuss with doctors and administrators.
Mark,
A few comments on your blog on this JAMA article. (1) Atul Gawande is incorrect – the improvement in mortality was not 17% but 0.17%! Given that the average mortality for the studied units was around 15%, that is a small imporvement. (2) Atul G. is also incorrect by asserting that 20% of the studied units used factory-like practices but had 17% lower mortality. What the article is saying is that 20% of the hospital units scored 4 or 5 on use of management practices. However, that does not necessarily translate into the 25th percentile when it comes to outcome measures. (3) I cannot find any discussion in the article concerning which of the 18 management practices had large or small impact. From what source have you taken those claims? And (4) what makes this JAMA article interesting is not just the solid methodology but also that the differences in outcome between the 25th and the 75th percentile units are quite small (see Table 5). One could argue that these small gains is a disheartening result.
I will have to double check the rest of it later, but the list of 18 management practices was in the supplement to the article, a separate PDF.
Urban – thanks again for pointing out my error. Looking at the paper, the “30-d risk-adjusted mortality rate” was 15.0 in the “bottom quartile of management score” and was 14.6 in the “top quartile of management score.” I’d calculate that as about a a 2.3% reduction.
The article says:
“In our study, a movement from the 25th to the 75th percentile in management scores was associated with a 0.17% reduction in mortality, a potentially important al- though modest improvement.”
I guess it can be “statistically significant” even if it’s just a small reduction? I’m with you, the results are actually a bit disheartening.
I also made an error, which I’ll blame on having the flu yesterday (resolved: no more blogging when sick)… the 18 management practices in the table were not listed in order of their impact on mortality.
This article states (as I had calculated) that the difference between the bottom quartile and top quartile was a 2.7% reduction in mortality.
I’d still wonder how much variation in management practices (and results) there was in that “top quartile” since I don’t think there’s 25% of organizations that have fully embraced lean management, say to the extent of a ThedaCare.
I’ve seen ThedaCare data that shows a near 100% reduction in mortality rates after cardiac bypass surgery.
I guess I will take the fork and spoon metaphor to its logical conclusion. As a physician and manager of a group, at the end of the day, we need to eat (improve). I will use whatever utensil gets the job done. I have found Mark’s books invaluable, because learning lean with his explanations and examples has been transformative in my thinking. Six sigma has been more of a tool, but if you are eating soup, you are going to want a spoon.
I agree. I am all for spoons. I am not willing to try eating soup with a spork. Using Lean and Six Sigma does not make it “Lean Sigma.”
During a visitor presentation at Virginia Mason 3 or 4 years ago the presenter was asked how they used statistical methods for improvement. The answer was, “we don’t”.