Root cause analysis (RCA) is the discipline of asking "why" until you reach a cause you can actually eliminate. Skip this and you fix symptoms forever.
Two techniques worth knowing
- 5 Whys - iteratively ask "why did that happen" until you reach an underlying cause. Usually takes 3-7 rounds, not always exactly five.
- Fishbone (Ishikawa) diagram - map possible causes across categories (People, Process, Equipment, Materials, Environment, Measurement). Structured brainstorming for messier problems.
Signs you've found a real root cause
- The cause is under your team's control to change.
- Fixing it prevents recurrence, not just this instance.
- It's a systemic condition, not a person's mistake.
- You can articulate it in one sentence.
Signs you haven't
- The "cause" is that someone made a mistake. (People make mistakes when systems allow them to.)
- The fix is training or awareness posters. (Real root causes rarely respond to information.)
- You could imagine the same thing happening again next month.