Find the root cause

Last updated August 25, 2026

A root cause is the thing that, if it had been different, would have stopped this happening. "Operator error" is almost never one - it is where the analysis stops when nobody wants to look further. Normiq gives you two structured ways to keep going.

Recording an analysis needs manage_capa_root_causes.

Five whys

Ask why the problem happened, then why that happened, and keep going. Five is a convention, not a rule: you have gone far enough when the next answer would be outside your control.

The root cause analysis card showing a five-why chain ending in a confirmed root cause.
Each why is a step in the chain, and the last one is what the actions have to change.

If your fifth why is a person, go back to the third. A process that depends on nobody ever making a mistake is the root cause.

Ishikawa

When the cause is not a single chain, the fishbone spreads the search across six categories - machine, method, material, people, measurement, environment - so a team can fill it in together without arguing about ordering first.

The root cause card showing an Ishikawa analysis with several categories filled in and the most probable one marked.
Fill only the categories that apply. Marking the most probable one is what turns the diagram into a decision.

  • Use five whys for a clear sequence of events, Ishikawa when several things had to line up.

  • Whichever you use, the confirmed root cause is a single sentence on the CAPA itself.

  • The analysis stays on the record - an auditor reads how you concluded, not just what you concluded.

Next: plan and complete actions.

Was this article helpful?