This is the third article of three (3). The titles of the three (3) articles are: THE FIVE (5) STEP MODEL; BRAIN STORMING METHODOLOGY; ROOT CAUSE ANALYSIS. The third and final article in this series focuses on the ROOT CAUSE ANALYSIS application.

ROOT CAUSE ANALYSIS - DEFINED: This is another subset to the PROBLEM - SOLVING PROCESS. It is employed multiple times - in the process step 2 – Problem Definition/Analysis and again in step 3 Problem Evaluation.

CONSTRUCTING A CAUSE & EFFECT (C/E) DIAGRAM:The steps involved in doing such are:

  • State the problem.
  • Determine the groupings – typically:
    • Materials, methods, measurement, machines/equipment, people, and environment
  • Conduct “Brainstorming” to list all the possible causes.
    • How is this done?
      • Using brainstorming technique of discussion and voting
  • Prioritize “KEY CAUSES”
    • HOW? – same as above – “Brainstorming” discussion & voting
  • Verify your determination of “Key Causes”.
    • This is done by assigning to a person who was a key contributor and advocate of these findings.
    • That person shall research and obtain data to support the conclusions reached:IN ALL THE YEARS I HAVE BEEN INVOLVED IN THE APPLICATION OF THIS TOOL, THE SUPPORTIVE DATA WAS ALWAYS OBTAINED – REASON BEING – the people involved in the use of this tool had the experience in dealing with and/or addressing the problem!

    A process also used, which doesn’t employ the diagramming as noted below, is called “THE FIVE (5) WHYS”! It is an exchange in questioning the parties involved, WHY, multiple times to drill down on the answers provided to each why. This is done until the responses no longer exist. This then would be verified as in the last step of Root Cause Analysis.


    The problem structured in the C/E Diagram below is “BAD TASTING COFFEE".