Root Cause Analysis
Looks for the cause behind the symptom — the point at which a measure removes the problem for good.
Also known as: RCA, root cause, causal analysis
Root cause analysis does not look for the place where a problem shows up but for the place where it originates. A root cause is reached when two conditions hold: removing it prevents recurrence, and it lies within the organisation's control.
- Containment action — removes the symptom and protects the customer; immediate, but not durable
- Corrective action — removes the root cause; slower, but lasting
- Preventive action — stops the same cause from acting elsewhere
The tools interlock rather than replace each other: Ishikawa collects hypotheses in breadth, 5-Why deepens the most promising one, Pareto and hypothesis tests substantiate it with data. Only the last step turns a suspicion into a cause.
See also
Used in
Sources
- Andersen, B. & Fagerhaug, T. — Root Cause Analysis: Simplified Tools and Techniques, 2nd Edition, ASQ Quality Press, 2006
- Ohno, T. — Toyota Production System: Beyond Large-Scale Production, Productivity Press, 1988
- Pyzdek, T. & Keller, P. — The Six Sigma Handbook, 5th Edition