knowledge assessment

By Mike Loughrin, CEO of Transformance Advisors

I’ll approach Lean Six Sigma as a contrarian!

It’s time for straight talk about the confusion surrounding lean six sigma.

The kind of discussion that will be uncomfortable for some.

The kind of discussion that will get some people angry.

I will be called a fool and told to take a long hike on a short pier.

Those with weak hearts should not read any further!

the truth about lean sigma

Lean and Six Sigma

Lean is defined as the systematic elimination of waste. There are other definitions, but most focus on waste.

Six sigma is defined as a structured approach for improving the quality of products, services, and processes by reducing variation with a goal of reaching less than 3.4 defects per million opportunities to have a defect. There are other definitions, but most focus on variation.

I have been very comfortable knowing that lean focuses on eliminating waste and six sigma focuses on reducing variation.

What does lean six sigma focus on?

Is it a jack of all trades and a master of none?

Ouch to that master of none possibility!

Putting lean and six sigma together brings us to the topic of this article:

From here on out, reader beware.

what is lean sigma

Confusion Reigns

lean sigma is confusing

What is Lean Six Sigma?

A posting on LinkedIn contained a plea from professor Tony Bendell seeking the definition of lean six sigma. At last count, he had received over 70 responses. Many respondents claimed to have the answer, but the sheer number of different definitions from so-called experts supports my assessment that:

There is no common understanding or definition of lean six sigma.

Professor Bendell’s take on the responses is: “My reason for asking the question was a debate we were having at the British Standards Institute. After receiving all that feedback on LinkedIn, it is very apparent that whilst, in general terms, the broad meaning of Lean Six Sigma is reasonably clear, there is, at present, an absence of a clear agreed definition. That is a shame, and adds to the problems caused by lack of adequate international standardization in this field. Not only is what people teach under this heading somewhat variable, but even what Lean Six Sigma is, is in doubt!


In an ideal world, we would blend the key concepts, tools, and approaches for lean and six sigma to create a hybrid super improvement program.


Besides eliminating waste and reducing variation, we should also look at the five principles of lean and the five step six sigma methodology.

Five Principles of Lean

  1. Specify Value
  2. Identify Value Streams
  3. Create Flow
  4. Leverage Pull
  5. Seek Perfection

Five Step Six Sigma Methodology

  1. Define
  2. Measure
  3. Analyze
  4. Improve
  5. Control


lean vs six sigma

While each program has 5 key concepts or steps as a foundation, these concepts or steps are not interchangable. We are comparing apples and oranges. A true blending of lean and six sigma would need to arrive at a different 5 principles or a different 5 steps or some other number of items that form the foundation of a new hybrid super program.

At present, I have not seen any willingness for lean experts to compromise on the 5 principles of lean and for six sigma experts to compromise on the 5 step DMAIC approach.

There has been no compromise and there has been no blending of these two methodologies!


Beyond the basic concepts, we should also look at the favorite tools used for lean and six sigma projects.

lean sigma tools

Primary Tools for Lean

  1. Value Stream Mapping
  2. 7 Types of Waste
  3. Kaizen Blitz Events
  4. The 5S System
  5. Changeover Reduction
  6. Pareto Analysis
  7. Poka Yoke

Primary Tools for Six Sigma

  1. Project Charter
  2. Voice of Customer
  3. Critical to Quality
  4. Standard Deviation Analysis
  5. Mistake Proofing
  6. Statistical Process Control
  7. Control Charts

There is considerable overlap and some of the tools are interchangeable. However, there are certain tools always used for lean projects and certain tools always used for six sigma projects. A true blending of the tools would require slight modifications, better integration, and a comprehensive understanding of using these tools in a new hybrid super program. For example: I can see using “Voice of the Customer” as a required tool during the “Specify Value” principle for lean transformations.


The third consideration is the approach used to manage the multiple projects when lean or six sigma is viewed as a strategic initiative.

what is lean

For organizations that view lean as a strategic initiative, one objective is achieving a cultural transformation where everyone in the organization is empowered to participate in continuous improvement efforts.

The goal is to create a sustainable organization.


For organizations that view six sigma as a strategic initiative, one objective is establishing a structure of yellow, green, black, and master black belts where employees have different levels of training and everyone participates in improvement efforts led by the black belts.

The ultimate goal is to reduce variability and achieve less than 3.4 defects per million opportunities to have a defect.

what is six sigma


In my opinion, there has not been a blending of the key concepts, tools, and approaches from lean and six sigma into a hybrid improvement program. I see many things that have been done and even more that could be done. The bigger issue is that people still follow their personal passions and primarily use knowledge and experience from lean or they use knowledge and experience from six sigma.

What I mean:

  • If you have a personal passion for lean, then you tend to view six sigma as one of the tools you can use during a lean transformation.
  • If you have a personal passion for six sigma, then you view lean as one of the tools used in the pursuit of reduced variation.

This inherent passion for either lean or six sigma doesn’t matter:

It Is What It Is!

Some of you may be exceptions to the rule, but my experience in talking with those that claim to be lean six sigma experts is that they are either 95% lean or 95% six sigma. I have not found the elusive expert who has blended the two improvement programs into a hybrid super improvement program.

lean sigma reality

Marketing Hype

lean six sigma nonsense

At this time, the most applicable definition for lean six sigma is:

three words used for marketing purposes by organizations that provide lean or six sigma consulting and training services.

These three words sound cool and new. Unfortunately, they mean different things to different people and have only succeeded in creating confusion.

At Transformance Advisors, we very seldom use the term lean six sigma. We are in that group focused on lean transformation programs. We leverage six sigma when there is a clear need to reduce variation using the five step DMAIC methodology. That’s what works for us. We have no qualms with someone running a six sigma project and using value stream mapping to find and eliminate waste. However, both methods do not rise to the level of saying you have integrated the two programs.

What This Means

When you see or hear the term lean six sigma, then think:

  • It’s lean and six sigma
  • It’s lean or six sigma
  • It’s marketing collateral
  • It’s time to be skeptical

Maybe, one day, you will actually be communicating with that elusive expert who has invested enormous time and effort into blending lean and six sigma into lean six sigma.

lean sigma checklist


lean sigma summary

Part of me always seeks to focus on the positive. My first thoughts concerning this article dealt with finding a definition that supported an ideal of a new hybrid super improvement program.

As reality hit home, I found that we are nowhere near the ideal of integrating lean and six sigma into lean six sigma.

Regardless of where we are, the future is bright. I expect the message of this article to become obsolete. At some point in time, we will see a blending of lean and six sigma.

The days of 70 LinkedIn postings with 70 different definitions will be a fond memory!

2018 Update

I’ve gotten lots of praise and some grumbling about this article.

Most lean enthusiasts agree 100%. The most common response is that lean and six sigma are two different approaches.

Pure six sigma enthusiasts are hard to find. But when found and asked, they agree that lean is different than six sigma.

Most lean six sigma enthusiasts are former six sigma folks that have converted in an attempt to extend their skills and stay busy. Their often tell me that I don’t understand what they are talking about. As you might suspect, I am not a fan of this response; if they can’t explain it well enough for me, then why am I the one who doesn’t understand?

lean sigma summary

Want More?

Read “What is Lean?”

Read “What is Six Sigma?”

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