How to Become a Lean Six Sigma Expert

Peter Robustelli Blog

Your organization is probably experiencing the same challenges that most of the ones I have engaged with have. They have a hard time choosing between simple Root Cause Analysis and using the Six Sigma methodology. Although the application of the Six Sigma methodology doesn’t have to be rigid, formal and complicated, it was designed for more complex problems than basic root cause analysis (RCA).

The challenge then lies with the selection of the right approach for the right type of problem. How would you best make this distinction? There are some simple rules that I can provide that will guide you in making these choices.

Six Sigma DMAIC:

  1. The problem is “chronic,” one that has been around for a while, raising its head regularly.  Something has been tried to eliminate or improve it, but all attempts have been met with limited success.
  2. The problem is “cross-functional” in nature. It crosses organizational boundaries and the source of the problem (organizational location) is difficult to identify. Typically this creates an environment of finger pointing and non-acceptance of the source between organizational leaders.
  3. There is an “absence” of understanding of what the root cause is. This relates to number one, but as that is an indicator of frequency, this is more of a validation of the mystery of “why” the problem even exists.

Root Cause Analysis:

  1. The problem is “sporadic” in nature. It shows up rarely and is usually tied to some special event or activity that has just occurred. This type of problem is driven by changes in behavior, process, measures, equipment or materials. This should sound familiar to many people who understand what a cause and effect diagram is.
  2. The problem is typically confined to a specific area of the organization, department, or facility. It is easy to pinpoint “where” it occurred but not the “why” it occurred. You can also easily select some internal subject matter experts to assist in the RCA activity.
  3. You can access and apply simple tools to diagnose the root cause by tracking back to the changes that may have occurred prior to, or during the execution of work. Some of these tools are:

Differentiating between when to apply the Six Sigma Methodology and Root Cause Analysis doesn’t have to be a mystery to anyone. By using these three simple criteria for each you can make the right decision.



For more information on how you can become a lean six sigma expert, please get in touch with the team.


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