Click to View One applies the 5 why problem solving tool to determine the root cause of a problem.
As customers become more experience in forcing suppliers to provide corrective action, they will request documentation that covers the 8D approach and 5Y analysis. This article deals with the five why analysis.
The Five Why Model In theory, one can easily learn this tool. In practice, this tool is much more difficult to apply. When a problem initially occurs, we all have an immediate reaction as to the cause of that problem. However, that immediate reaction is a surface reaction only. When it comes to examining processes or systems, there are other deeper root causes for that problem. How does the 5Y tool work?
Here is a quick flow The primary root cause or key root cause directly determines the other sub root causes. When solving the problem, you focus your efforts on the key root cause. For each why question, you focus on the last sub root cause. When applying this tool, asking “why” 5 times may not be necessary. You may only need to ask “why” 3 times to come to the correct root cause.
The number 5 is an arbitrary number. The 5Y method is a process of asking why a sub root cause occurred until you reveal the key root cause.
When doing the 5Y analysis, use a team approach to determine the root causes. Document each determined sub root cause. When you identify the key root cause, be sure to positively identify that root cause on your document with a check mark or underline. Additional 5Y Actions As mention above asking “why” five times may not be sufficient, you may need to ask more than 5 times.
Once you determined the key root cause from the 5 why problem solving methodology process you are not finished with the 5 why analysis.
You need to verify that root cause. You verify the key root cause by witnessing the root cause in action. Then check to see that you duplicated the problem.