Are Agile and Six Sigma Complementary to Each Other?

I recently responded to a question on an online discussion that asked “Are there companies that use Agile and Six Sigma?”.  This raises an interesting question of “Are Agile and Six Sigma really complementary to each other?”.


Are Agile and Six Sigma Really Complementary to Each Other?

The objectives behind numerous approaches such as:

  • Agile and Six SIgma,
  • Agile and Lean, and
  • Agile and Waterfall

are very different and if you pursued these approaches individually and independently of each other, the objectives of each approach are probably somewhat contradictory.  However, all of these approaches can be blended together in the right proportions if they are implemented intelligently in the right context.  That requires a lot more skill and it requires a different kind of thinking to see them as complementary rather than competitive approaches.

The Fundamental Problem

There is a significant fundamental problem that must be overcome to see all of these approaches in a different perspective:

  1. Companies and individuals get enamored with a methodology like Agile or Six Sigma and see it as a “silver bullet” solution to any problem that they might have
  2. They attempt to mechanically force-fit their business to one of those methodologies without fully understanding the principles behind it

An Example With Six Sigma

When I published my first book a long time ago in 2003, Six Sigma was very hot at that time and everyone wanted to “jump on the Six Sigma bandwagon”.  At that time, I researched a number of companies that were doing Six Sigma and other process improvement methodologies and what I saw was this:

  1. Successful Companies – In companies that seemed to do Six Sigma successfully:
    • It wasn’t even obvious that it was Six Sigma and they might not have even called it “Six Sigma”,
    • The implementation wasn’t limited to Six Sigma, they understood the principles behind Six Sigma, and might have blended Six Sigma with other process improvement methodologies, and
    • It was so well-integrated with their business, that it was just a tool that was part of their business rather than a program that was superimposed on their business
  2. Less Successful Companies – In other companies, I saw a much more superficial implementation of Six Sigma that didn’t last in many cases:
    • There was a lot of emphasis on the “mechanics” of doing Six Sigma,
    • There was a lot of “hoopla” about the ceremonies associated with Six Sigma – green belts, black belts, etc., and
    • They openly advertised that they were using Six Sigma to promote themselves

Does that sound familiar?  I think a similar thing is going on with Agile today.

The Key Factor for Success

What I learned from that some of the key factor for success are:

  • Don’t get overly enamored with any methodology (Six Sigma or anything else) and see it as a “silver bullet” for any problem you might have.  Be objective and recognize that any methodology has advantages and limitations depending on the problem you’re trying to solve,
  • Adapt the methodology to fit the problem and the business environment rather than force-fitting your business to some predefined methodology, and
  • Go beyond simply doing a mechanical implementation of any methodology (Agile or Six Sigma) and understand the principles behind it at a deeper level

Are Agile and Six Sigma Really Complementary To Each Other?

Any company who takes that kind of superficial, mechanical approach is going to have difficulty seeing how seemingly competitive and contradictory approaches might actually be complementary to each other. Here are a few examples:

  1. Agile and Six Sigma – On the surface, Six Sigma and Agile would tend to pull you in different directions:
    • Agile emphasizes creativity and innovation as well as flexibility and adaptivity to maximize the business value of the solution
    • Six Sigma emphasizes process standardization and control of a process to minimize process variation
  2. Agile and “Waterfall” – You could make a similar comparison about Agile and Waterfall:
    • Agile emphasizes flexibility and adaptivity and encourages changes as the project is in progress to maximize the business value of the overall solution
    • Plan-driven approaches (what many people loosely call “Waterfall”) emphasize planning and control and discourage changes as the project is in progress to maximize predictability
  3. Lean and Agile – You could also make a similar comparison about Lean and Agile:
    • Lean emphasizes standardizing processes and removing waste from a process to improve process efficiency
    • Agile requires a process to be flexible and adaptive

How Can These Approaches Be Complementary Rather Than Competitive?

How can all of these different approaches that have different objectives that seem to be contradictory to each other actually be complementary to each other rather than competitive? For example, there are many people who see “Agile” and “Waterfall” as binary and mutually-exclusive choices and don’t see any way that the two approaches could be combined.

The key to seeing these approaches as complementary rather than competitive is to understand the fundamental principles behind the approach at a deeper level rather than getting lost in the “mechanics” of the approach. For example:

  • “Waterfall” – The word “Waterfall” has some well-ingrained connotations associated with it that are not necessarily totally accurate.  It invokes an image of a very bureaucratic process with phases that are rigidly-controlled so that you don’t exit that phase until you have completed all of the onerous documentation requirements for exiting that phase.   That process that was originally documented by Winston Royce in the 1970’s and is rarely used in that form in practice today; however, the word “Waterfall” continues to be used very loosely for any process that is not Agile.

    The fundamental essence of what people call “Waterfall” is that it is a “plan-driven” approach – that is why I prefer to call it “plan-driven” instead of “Waterfall”.  A “plan-driven” approach does not necessarily have to have a rigid and inflexible plan and it also doesn’t necessarily have to have many of the other attributes of the original Waterfall approach such as excessive reliance on documentation and phases that have controlled phase transitions.

  • “Agile” – The word “Agile” has also taken on some very heavily-ingrained connotations in practice today.  When you say the word “Agile” many people associate it with Scrum and think that you can’t be “Agile” unless you are really following all the rituals and ceremonies associated with Scrum religiously.

    The fundamental essence of “Agile” is being flexible and adaptive to maximize the value of the solution that is being produced.  I prefer to use the word “adaptive” rather than “Agile” for that reason.  The word “adaptive” is a more general term that does not carry some of the heavily-ingrained connotations associated with the word “Agile”.


  • Lean – The essence of Lean is the reduction of waste in a process and there is absolutely nothing wrong with that as long as people don’t become obsessive about reducing waste at the expense of other objectives.  For example, in an Agile process, it is impossible to completely remove waste; and, at the same time, attempt to maximize the flexible and adaptive which is the essence of being Agile.  However, there is nothing wrong with trying to reduce waste in an Agile process as long as it is done intelligently and in the right balance with other objectives.

  • Six Sigma – The essence of Six Sigma is attempting to standardize processes and reduce variation in processes.  If you became obsessive about pursuing that goal, it would also not be very consistent with being Agile; however, there is absolutely nothing wrong with attempting to standardize processes to some extent as long as it is also done intelligently and in balance with other objectives.

The importance of “Systems Thinking”

A fundamental skill for doing this successfully is “Systems Thinking”. Here’s a definition of “Systems Thinking”:

“Traditional analysis focuses on separating the individual pieces of what is being studied; in fact, the word ‘analysis’ actually comes from the root meaning ‘to break into constituent parts’. Systems thinking, in contrast, focuses on how the thing being studied interacts with the other constituents of the system – a set of elements that interact to produce behavior – of which it is a part. This means that instead of isolating smaller and smaller parts of the system being studied, systems thinking works by expanding its view to take into account larger and larger numbers of interactions as an issue is being studied.”

Overview of Systems Thinking –


What is Systems Thinking?

This kind of thinking is essential for seeing these seemingly contradictory approaches in a much broader context of how these objectives can interact in complementary ways rather than being competitive.

Overall Summary

It is very possible to blend together different approaches that are seemingly in conflict with each other as long as it is done intelligently. It requires:

  • Understanding the fundamental principles behind each approach rather than getting lost in the mechanics,
  • Using a systems thinking” approach to see how these seemingly contradictory approaches might actually be complementary to each other rather than competitive, and
  • Learning to fit the methodology to the problem rather than force-fitting a problem to any given methodology or combination of methodologies

This is exactly the approach behind the Agile Project Management online training courses I’ve developed.