Why why analysis

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Why why analysis
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Methods and techniques

Why why analysis is a method of searching for and finding the root causes of the problem. The name of the method comes from the main question asked during the analysis: Why? Thanks to asking that question many times it is possible to find real, often hidden causes of the problems. Dealing with real causes prevents the problem from happening again.

The method is an evolution of Fish diagram created by Kaoru Ishikawa. The why why analysis is used mainly in Six sigma, however it can be used in every organization. The idea of 5 whys comes from Genichi Taguchi, who once said that to find the real causes you need to ask why five times.

Procedure of why why analysis

The analysis should be performed by a team of people interested in finding solution to the problem. The team should be diversified to assure different points of view. The team should consist of not more than 12 people.

Usually the best tool for the analysis is large blackboard or flipchart. However the analysis can be performed using computer, beamer and mind mapping application, such as free Freemind.

The procedure is as follows:

  1. Start with the problem you'd like to solve. Ask "Why does the ... take place?" That's a first why. Write this question in the centre of the blackboard/flipchart.
  2. Write the answers to the question. Write each answer on one line coming from the main question. It will be convenient to draw each line in slightly different direction.
  3. For each of the answers ask again "Why does the ... take place?". And write down the next level answers on new lines coming from the first level ones. This way a kind of net is created.
  4. Repeat the same on the next levels until you get the 5th level. Then stop.
  5. When you hit the 5th level you usually have most of the causes identified, including the root ones. They are not always on the 5th level. Some of them can arise on higher levels. For each root cause identify potential actions that reduce possibility of occurrence or result of that cause.

Example of why why analysis

In this example the problem is lack of money. We have found three possible causes of it. Every cause was analysed further. The example has only two levels due to lack of space. The full analysis should be five levels deep. Whywhyanalysis.png

Effective why why analysis

Keep to the following rules:

  • Involve the right people. They should be familiar with the problem and process. They should be from different departments if possible. There shouldn't be superiors and subordinates in one group. Sometimes it's good to add some people that don't know the process/problem. They can present a fresh look.
  • Avoid blaming for problems - The aim is not to find guilty, but to solve the problem. Stop each argument that leads to blaming someone immediately.
  • Get creative - use brainstorming to enable people and their creativity. Try some ice breakers for starters.

Benefits of why why analysis

  • Helps to identify the root causes of the problem and distinguish them from less important ones.
  • Determines relations between causes.
  • Doesn't require statistical analysis.
  • Very simple and quick tool

Constraints of why why analysis

The simplicity is not always a good thing. When it comes to sophisticated problems it might prevent from finding a solution. The why why analysis is quick, however it shouldn't be the only one method in manager's methods portfolio. The typical problems are:

  • Stopping at symptoms, not the real causes
  • Limited knowledge of the team who can't find additional causes
  • Lack of ability to ask the right why? questions
  • Dependability on team competences - different team can find different causes
  • Stopping at first root cause, where there is a set of root causes


Author: Slawomir Wawak