Why DMAIC Endures as a Robust Thought Process

From time-to-time, there are new ways of thinking or shortcuts to solving problems.  However, the tried-and-true Define-Measure-Analyze-Improve-Control (DMAIC) thought process endures as a fundamentally robust problem-solving thought process.

DMAIC must be properly applied to be effective, however.  In this article we’ll consider some important objectives within each DMAIC sub-process.

First, let’s consider each sub-process as an opportunity to perform collaborative problem solving.  In the “Define” phase (for example) the stakeholders and team members mutually agree on the problem statement, goals & objectives, process under study, process start/stop points, team members, business impact, etc.

While a project charter is an effective tool to enable “Define” information to be collected from team members, this article will focus on critical thinking (not tools) as follows:


  • The problem statement is mutually agreed, the team is working on the ‘right’ problem and headed in the right direction.
  • We set-out to discover our “Y = f(x)” where the problem is our “Y” output as a function of multiple input (x) variables.


  • We verify the problem isn’t caused by a faulty measurement system.
  • We verified the problem with an adequate measurement system and establish our output (“Y”) that needs improvement.
  • We can detect variability in our output (“Y”) and relative improvement as progress is made.
  • We identify multiple variables that could be contributing causes of the problem.


  • We analyze multiple variables and identify the “critical few” that are the contributing causes of the problem.
  • We defined our Y=f(x) relationship, were Y = effect and (x) = causes.


  • With our knowledge of the input (x) variables contribution to the output (Y), we implement targeted improvements through design or process improvements.
  • We validated improvements as having effectively solved the problem.


  • We control variability of the critical input (x) variables in order to ensure the output (Y) problem is solved. This includes ensuring adequate measurement, monitoring and controls in order to maintain variability within an acceptable range.

Arguably, DMAIC could turn problem solving into somewhat of a science project.  This can be avoided by identifying quick-win actions and forging ahead while continuing to apply DMAIC critical thinking.  Also, several risks exist by skipping any one of the main objectives above.

In addition to six sigma tools, DMAIC helps the team think similarly throughout the project, and ensure the problem is solved with validated and sustainable improvements.