Tech Leaderism

Five Whys

The Five Whys method is a simple but powerful tool used to identify the root cause of a problem by asking "why?" five times in succession. It was originally developed by Sakichi Toyoda and became a foundational part of the Toyota Production System and lean manufacturing practices.

The process starts with a clear statement of the problem. From there, you ask "why did this happen?" and then continue asking "why?" for each answer you get. The idea is that each answer brings you closer to the underlying cause, not just the surface symptom. You usually reach a root cause by the fifth "why" but it could take more or fewer steps depending on the situation.

Example: The car won't start.

1. Why? - The battery is dead.

2. Why? - The alternator isn't working.

3. Why? - The alternator belt is broken.

4. Why? - The belt was worn out and not replaced.

5. Why? - The car wasn't maintained on schedule.

Root cause: Poor maintenance practices.

The Five Whys is best for straightforward problems. For more complex ones, it's often combined with other tools, but on its own, it's a great way to get past quick fixes and understand what really needs to change.