5 whys Analysis

5 Whys Analysis is a tool that allows you to methodically go from the problem statement to root cause simply by asking “why?”.

The goal is to keep asking “why” until you can no longer ask anymore. Once this is the case, you have reach the “true” root cause of the problem.

There are 3 “paths” in a traditional 5 Whys Analysis:

  1. Specific defect that was produced – this path will find out why the defect happened.

  2. Specific defect was not detected – this path will find out why the defect was not detected.

  3. Specific defect was allowed to exist – this path will find out why the overall system allowed the defect to be produced.