five-whys

Start with a specific, measurable problem statement, then ask "why" iteratively, documenting each answer with evidence. Continue until you reach a systemic process cause, typically around five levels, then design solutions targeting that root cause rather than symptoms.

The Five Whys technique investigates root causes of recurring problems, system failures, customer churn, and project delays. Originally developed by Sakichi Toyoda for Toyota, it traces symptoms back through causal chains to underlying process failures.

Five is a guideline, not a rule. Continue asking why until you reach a systemic process cause you can act on, which may take three or seven iterations. Stop when further answers no longer reveal actionable process improvements.

Analysis fails when teams stop at surface symptoms, rely on assumptions instead of data, or blame individuals instead of processes. Verify each answer with evidence, involve diverse perspectives, and confirm that fixing the identified cause would prevent recurrence.

Yes, Five Whys works alongside Fishbone diagrams for visualizing cause categories, Pareto analysis for prioritizing problems, Six Sigma DMAIC, and post-mortem reviews. Combining methods helps when problems have multiple contributing root causes.