< Methods

Root cause analysis



Understand why a problem occurs and prevent it from happening again.


Systematically identify the possible factors that could have led to the problem. For each factor, determine whether it is symptom of a deeper cause. Classify the factors and define measures to prevent the problem from happening again. Do not stop too quickly; ensure that there is no deeper cause.


  • A structured approach.
  • No initial bias about possible causes or solutions.
  • A diverse group of knowledge holders to help (e.g. security, software, business, user perspective).

In practice

Companies use many techniques (e.g. fishbone diagram, problem tree, 5x why). One example is a software company that put more and more effort into testing because of bad product quality. By using 5X Why, they discovered that the root cause was over-optimistic scheduling that led to stress for the developers.

Phase(s) of use

In the following project phase(s) root cause analysis can be used:

  • Problem definition
  • Analysis