5 Why Root Cause Analysis (RCA) – One Point Lesson (OPL)

5 WHY Analysis is the key tool used to determine ROOT CAUSES for the Phenomenon identified in the
CHECK Phase of CAP-Do.

1. The 5 Why analysis begins with the Summary of the Phenomenon from the 5W 1H analysis.
2. The first “why?” originates from the Summary of the Phenomenon.
3. The answer to the “why?” question (from the Summary of the Phenomenon) becomes the question of the second “why?”
4. Follow this sequence until a root cause has been identified (through an answer to a “why?” question).

Note:  If a root cause is identified before the 5th “why?” then the analysis is finished.  It is unnecessary to complete all 5 whys if a root cause is identified early in the analysis.