Mostly used in root cause analysis, five Whys obviously appear in the Analyze phase of DMAIC in Six Sigma. This method iteratively inquiring in nature, basically used to recognize the root cause or defect, was introduced by Sakichi Toyoda and practiced in the Toyota Motor Corporation.
Experts have different views about this methodology which is often completed by a fish-bone diagram. There is no only one root cause if perceived closely. Generally, it is a series of events or a mixture of factors. Detection of the defect is a critical challenge and there are different methods and techniques. One such popular technique is 5-why. This is useful to list out the top 5 root reasons which mainly contribute to the problem.
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The technique may sound simple but very effective. The question is frequently posed from the answer given and it is an iterative model. You should try and portrait as some day-to-day problems you find yourself solving by finding the main reason, like the percentage of your kid in a just held test paper. It is as more questioning your kid “why did you get fewer grades?” and from the answer given by your kid, there is a quick question-answer, till you are influenced one way or the other.
Why did your grades dip?
I didn’t do the exam properly.
Why didn’t you do the exam properly?
I couldn’t answer most of the questions.
Why couldn’t you answer most of the questions?
The questions were not familiar.
Why weren’t the questions familiar?
I had not prepared well enough.
Why didn’t you prepare?
Because I was playing and missed the time to prepare.
Lastly, it is the absence of preparation that directed to the lowly performance. This may be your decision drained from the conversation. And the suggestion or sequence of action is to ‘gear up better and be most prepared to face the next test.’
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Use the same to a project to evaluate a disappointment – which we consider it the root cause analysis There is no predefined rule to break the questioning at 5-level. It should go ahead. General researches state that ‘5 why’ generally lead to the main reason(s) of disappointment.
This technique suffers from its own share of limitations. The method stops at the symptoms level and flops to dig cavernous at the lower-level main causes. The outcomes not being repeatable is the main aspect of this method. As well, ‘Why’ can lead to different root causes but there is a leaning to separate a single main cause and stick to it. The shortfalls aside, 5 Whys is nonetheless is suggestively used in Root Cause Analysis (RCA).