What is Root Cause Analysis?
Root cause analysis investigates why a problem occurs so corrective action can address contributing conditions rather than only its visible symptom. The Five Whys and fishbone methods help structure that investigation.
When to use it
Use it when a problem recurs or its symptoms do not explain what is happening.
How the methodology works
Use the 5 Whys technique and Fishbone (Ishikawa) diagram to systematically identify the root causes of problems before making decisions.
- Describe the problem with a specific event, scope, and evidence rather than an assumed explanation.
- Ask why the event occurred and follow contributing causes. Use the fishbone categories to look beyond one person or one step.
- Check proposed causes against evidence, then define a corrective action that addresses a cause and a way to see whether the problem recurs.
Example: Recurring delays in customer orders
Illustrative situation: Orders are repeatedly dispatched later than planned. The first explanation is that staff are slow, but timestamps show many orders wait before inventory status is updated.
How to apply it: The team can trace how the update is handed off, use the fishbone categories to check process, system, staffing, and measurement factors, then test a corrective action at that handoff.
Example limits: This scenario is illustrative, not evidence about a real business. Use evidence relevant to your decision for your own facts, ratings, probabilities, or financial estimates.
How to read the result
Keep asking why until you reach a root cause, focus on causes you can control or influence, and turn them into specific, measurable corrective actions.
Questions about Root Cause Analysis
How many times should I ask why?
Five is a prompt, not a rule. Continue while each answer is evidence-based and useful. Stop when you reach a cause that can be verified and acted on.
Is the first cause I identify the root cause?
Not necessarily. Treat it as a hypothesis, check it against evidence, and look for other contributing causes before settling on an action.
Next step
Write one observable problem and its evidence, then trace causes before choosing a corrective action.
Need a printable resource or a step-by-step method? How to analyze a business situation. Select an analysis method for a defined operational or strategic question.