This process uncovers the real, or root, cause of a problem instead of creating workarounds. The root cause is one that, if corrected, prevents recurrence of the issue.

Why use root cause analysis?

When people discover problems, the most frequent response is to rush to find a solution. Unfortunately, it is not the best way to solve a problem as it leads to the need to solve the same problem over and over again. A better approach is to eliminate the root cause.

What is root cause analysis?

It is a systematic process to uncover the real cause of the problem. Many problem-solving processes manage a symptom of the problem rather than eliminating the root cause of the problem. The root cause is one that, if corrected, would prevent a recurrence of the problem.

How do we do it?

Collect a sample of data related to the problem and conduct a root cause analysis to identify the reasons why the problem exists. This analysis will form the basis for determining solutions that will prevent any recurrence of the causes, and ultimately, the problem.

A simple form of root cause analysis which does not require advanced statistical tools is the '5 Whys'. It is most useful for problems which involve human factors or interactions. By repeatedly asking the question 'Why?' (five is a good rule of thumb), you can peel away the layers of symptoms which can lead to the root cause of a problem.

  1. Write down the specific problem. Writing the issue helps formalise the problem and describe it completely. It also helps a team focus on the same problem.
  2. Ask why the problem happens and write the answer down below the problem.
  3. If the answer you just provided doesn't identify the root cause of the problem that you wrote down in Step 1, ask why again and write that answer down.
  4. Loop back to Step 3 until the team is in agreement that the problem's root cause is identified. Again, this may take fewer or more times than 5 Whys.

Example — Root cause analysis using 5 Whys

Problem statement: You're on your way home from work and your car stops in the middle of the road.

Why did your car stop?
Because it ran out of petrol.
Why did it run out of petrol?
Because I didn't buy any petrol on my way to work.
Why didn't you buy any petrol this morning?
Because I didn't have any money.
Why didn't you have any money?
Because I don't know how to budget my money.
Why don't you know how to budget?
Because I have never set aside time to learn how.


Process map of root cause analysis flow