Analyzing by Five Whys
5-Whys is a part of the RCA [Root Cause Analysis] aspect that was developed by the Japanese inventor and industrialist Mr. Sakichi Toyoda for Toyota’s manufacturing processes in 1958. Also, used as a technique in the Analyze phase of the Six Sigma DMAIC (Define, Measure, Analyze, Improve, Control) methodology
It is a brainstorming tool by an iterative interrogative technique used to explore the cause-and-effect relationships underlying a particular problem to help the team identify the root cause(s) of a matter or a problem.
The concept here is by asking "Why?" five times successively, can you delve into a problem deeply enough to understand the ultimate root cause.
As by the fifth why the auditor should have identified or be close to identifying the root cause of the issue.
• The answers come from people who have hands-on experience of the process or problem in question.
• It can be used to complement the analysis necessary to complete a Cause & Effect diagram.
• This methodology is can related to the Cause & Effect (Fishbone) diagram.
The vehicle will not start. (The problem)
1. Why? : The battery is dead.
2. Why? : The alternator is not functioning.
3. Why? : The alternator belt has broken.
4. Why? : The alternator belt was well beyond its useful service life and not replaced. (Fourth why)
5. Why? : The vehicle was not maintained according to the recommended service schedule. (Fifth why, a root cause)
The 5 Whys technique is an effective tool for root cause analysis in Lean management.
In workplace staffs face roadblocks in its daily work, the 5 Whys technique is simple also, effective tool for solving issues.
by finding the real reason for a given problem by asking a sequence of “Why” questions and eliminate these reasons ( answers) and to be sure that it will not be repeated in the future.