The 5 Whys
Last updated
Last updated
The Five Whys is a simple yet powerful problem-solving technique used to identify the root cause of an issue by asking "Why?" five times in succession. Developed by Toyota as part of its Lean manufacturing processes, this method aims to move beyond surface-level symptoms to uncover deeper, underlying problems. Each answer forms the basis of the next "Why?" question, allowing teams to trace the issue step by step until the root cause is found. While it doesn't always require exactly five iterations, the focus is on continuing until a fundamental cause is revealed, leading to more effective and lasting solutions.
Example 1: Toyota
Problem: High number of customer complaints about a specific car model.
Five Whys:
Why are customers complaining?
Because the car's engine is noisy.
Why is the engine noisy?
Because a specific engine component is vibrating excessively.
Why is the component vibrating?
Because the component was not manufactured to the correct specifications.
Why wasn't the component manufactured correctly?
Because the manufacturing equipment was not calibrated properly.
Why wasn't the equipment calibrated properly?
Because the maintenance schedule for the equipment was not followed.
Example 2: Healthcare Provider
Problem: High rate of patient readmissions after surgery.
Five Whys:
Why are patients being readmitted?
Because of post-operative infections.
Why are patients getting post-operative infections?
Because of inadequate hygiene practices in the post-operative ward.
Why are hygiene practices inadequate?
Because staff are not following the correct protocols.
Why are staff not following protocols?
Because they are not adequately trained.
Why are staff not adequately trained?
Because there is a lack of resources allocated for training.
Example 3: Tech Company
Problem: Frequent software crashes.
Five Whys:
Why is the software crashing?
Because of a memory leak in a specific module.
Why is there a memory leak?
Because of a coding error in the module.
Why was there a coding error?
Because the developer was not following coding standards.
Why wasn't the developer following coding standards?
Because the developer was not adequately trained on coding standards.
Why wasn't the developer trained on coding standards?
Because the company's training program was not effective.
