The Five Whys is a root cause analysis technique developed within the Toyota Production System and introduced by Sakichi Toyoda. It is disarmingly simple: ask 'why?' five times in succession, with each answer becoming the input for the next question. The process drills past the presenting symptom of a problem to its underlying cause, which is almost always different from the surface-level explanation and far more important to address. It is one of the fastest and most accessible tools for moving from problem description to problem understanding.
Five Whys
Drilling past symptoms to the root cause of any problem
A
Designers Academy
29 July 2026 · 4 min read
UXMethods
In brief
The Five Whys is a root cause analysis technique developed within the Toyota Production System that involves repeatedly asking "why?" to drill past a problem's symptoms to its underlying, actionable cause.
