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The 5 Whys Method: A Root Cause Analysis Tool

In the last QSSI Blog, we talked about how root cause analysis (RCA) can save us from wasting time, money & other resources addressing the same problem over and over again. Today we look at one common method of RCA called the 5 Whys method.

What is the 5 Whys Method?

The 5 Whys method was developed by Sakichi Toyoda, the Japanese founder of Toyota Industries, in the 1930s. It is most effective in resolving simple or moderately difficult problems. Simply put, the 5 Whys method entails asking the question ‘Why?’ enough times to get to the root cause of your problem.

How do you perform the 5 Whys?

1. Form a Team

The 5 Whys exercise is most effective when done by a team of people who have hands-on experience with the process being examined.

2. Define the Problem

Develop a clear and concise problem statement that keeps the focus on the process not the personnel. Additionally, determine the quantitative and/or qualitative impact on the business

3. Ask Why

An assigned team leader or facilitator should ask “Why” the problem occurred. The team then should provide responses that are backed by facts or data. The responses should also focus on process or systems errors.

If the identified causes were corrected and the problem could still occur, the team should then move on to the second “Why” and then the third, fourth, fifth and so on until you have determined the root cause for the system failure. 

4. Monitor Your Measures

Finally, you need to monitor to see how effectively your corrective actions eliminate or minimize the initial problem. You may need to adjust or change them entirely. If this happens, it’s a good idea to repeat the 5 Whys process to ensure that you’ve identified the correct root cause.

 Things to Note: 

  • The “5” in 5 Whys is just a “rule of thumb .” It is not always necessary to ask “Why” five times. The root cause could be identified by the third or fourth “Why”. It may also take more than five times to get down to the root cause.
  • Don’t ask too many Whys. If you keep going, you may end up getting a barrage unreasonable suggestions and complaints, which is not the point. Focus on finding the root cause.
  •  Sometimes there could be more than one root cause. In these cases, the 5 Whys diagram will look more like a tree with different branches.
  •  Determine and Implement Corrective Actions; once you’ve arrived at the root cause(s), you can now make a list of appropriate corrective actions to address each root cause.

5 Whys Example

Here is a simple example:

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In Summary:

The 5 Whys method:

    • Can help a team focus on finding the root cause of any problem.
    • Allows each team member to share ideas for continuous improvement.
    • Gives your team the confidence that it can eliminate any problem.

This is just one of the techniques that QSSI can teach your team in RCA training so that they can be a confident problem-solving machine! Want to find out more? Contact us today.