Root cause identification

Getting to the root cause of a problem and resolving the issue at the most fundamental level is what we would always prefer to do, but how do you get to the root cause? And is there actually such a thing as a single ultimate root cause?

There may not be an answer to the latter question, but what we do know is that there are differing levels of problem causation and getting to and resolving the deepest level possible is what will give us the greatest improvement effect.  There are many different root cause identification techniques and we advocate two of the most well-known / well proven of them:

  • 5 Why's
  • Cause & Effect Diagrams (aka Ishikawa Diagrams)

The method for each is outlined below and you can use these techniques in many different settings.  There are no right or wrong answers when you use the techniques, only more or less understanding of the problem you are considering, but any increased understanding is a positive. 

The more you use a technique the more comfortable and adept you will become in using it, so at the outset don't worry about 'doing it right', just use it to help you and your team with understanding and insight.

5 Why’s

The 5 why’s technique simply requires you to ask ‘why?’ several times in relation to the problem you are considering. The technique is called the ‘5 why’s’ because this is often the number of times ‘why’ is asked before getting to the root cause.

However, what this technique is really all about is having a questioning attitude and not accepting the first reason given. It is all about probing beyond this answer in a curious and questioning way, but never in an aggressive, demanding or accusatory way. 

The steps in undertaking a 5 why analysis are:

  1. Determine your starting point for the analysis – perhaps the problem itself or a possible cause that you want to explore further
  2. Use your / your teams curious and critical thinking to ask ‘why’ this is a problem or possible cause
  3. Depict the chain of causes as you progress through asking ‘why’ to each previous answer
  4. Keep going until you can no longer answer ‘why’ – this is most likely the root cause, or the deepest cause you can currently get to

This is a simple technique but not an easy one; it requires effort and for you to exert your critical thinking on the answers you come up with. Are you making assumptions in your answers? Do you understand the issue sufficiently to answer ‘why’? Do you need other people to be involved in answering it?

Cause & Effect (Ishikawa) Diagrams

The cause and effect diagram technique does what it says on the tin – it is tool that helps understand the relationship between a problem and its causes. This is a technique that combines aspects of brainstorming together with a more systematic cause analysis and can be used to:

  • Generate and group problem causes
  • Systematically evaluate cause and determine likely root causes

The technique uses a format often referred to as a ‘fishbone’ to capture the problem and potential causes – see picture below. The steps in creating a cause and effect diagram are:

  1. In the right hand side of the page (the ‘head’ end of the fishbone) clearly and succinctly describe the problem that you are seeking the causes of

  2. Identify the main categories of possible problem cause and write them at the top of main branches from the ‘backbone’. You can identify whichever categories make sense to your situation, but a classic set are:

    People
    Methods
    Environment
    Equipment
    Materials
  3. Brainstorm and write all the possible causes under the cause categories, using brief and succinct descriptions, working through one category at a time to drive out as many possible causes as you can. If a cause goes in more than one category, put it under all that are applicable

  4. After you have brainstormed the causes, you need to analyse them to determine the most likely root causes. You will want to check these with data or observations.

Remember, these are the things that you will spend your time developing and testing solutions for, so you want to get to the best analysis possible.  Use your critical and curious thinking to help in conducting this analysis. 

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