The 5 Why’s Analysis

The Five Why’s analysis, also known as the root cause analysis is one of the seven basic tools that are used in Six Sigma. The principle idea behind the tool is the fact that for every effect there is a cause. Therefore the quality problem can be viewed as an effect for which there will be one or multiple causes. However, it is also known that there is a whole chain of reactions called symptoms before the cause actually reaches its effect. Therefore if the management is able to pinpoint and solve the problem from its root cause, considerable advantages would be gained.

Jeff Bezos Amazon Example of Application of Five Why’s:

Jeff Bezos illustrated, how the Five Whys can be used. He had visited one of the shop floors at Amazon. On his visit he saw that the fingers of one of the employees was caught in the conveyor belt and the employee had sustained injuries. Below is an account of the meeting in which Mr Bezos discussed this incident.

Question: Why did the associate damage his thumb ?
Answer: Because his thumb got caught in the conveyor.

Question: Why did his thumb get caught in the conveyor?
Answer: Because he was chasing his bag, which was on a running conveyor.

Question: Why did he chase his bag?
Answer: Because he placed his bag on the conveyor, but it then turned-on by surprise

Question: Why was his bag on the conveyor?
Answer: Because he used the conveyor as a table

Conclusion of the Case

So, the likely root cause of the associate’s damaged thumb is that he simply needed a table, there wasn’t one around, so he used a conveyor as a table. To eliminate further safety incidences, we need to provide tables at the appropriate stations or provide portable, light tables for the associates to use and also update and a greater focus on safety training. Also, look into preventative maintenance standard work.

Conclusion Regarding the Methodology in General

The Five Why’s act as a powerful tool and help in sifting through the symptoms which represent surface level problems to the real problem, the root cause. Solving this root cause solves all the problems in between.

Subjectivity Involved

The Five Whys process is only semi-structured. This means that if it is done by different people, they may come to very different results. The process therefore is only as good as the person running it. This makes it important to ensure that the team is cross functional and really involved in obtaining best results for the process.

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