For quite a while I have been waiting for an opportunity to try a 5-why root cause analysis in a sprint retrospective.
The 5-why analysis has its origins within Toyota and lean manufacturing and is used to find the root cause of a problem through identifying a symptom and then repeating the question “Why?” five times. General wisdom and experience state that the nature of a problem and its solution usually become clear after 5 iterations of asking “Why?”.
Here’s an example from wikipedia:
Problem: My car won’t start.
- Why? – The battery is dead.
- Why? – The alternator is not functioning.
- Why? – The alternator belt has broken.
- Why? – The alternator belt was well beyond its useful service life and has never been replaced.
- Why? – I have not been maintaining my car according to the recommended service schedule.
Solution: I will start maintaining my car according to the recommended service schedule.
I have found 5-why root cause analysis very useful in the past but had never tried it with a group of people or a software development team.
I “conspired” with our very talented Scrum Master and the plan was to share data from previous sprints, analyse the data as a team and see if we could identify a problem. If so, we would suggest a 5-why analysis to see whether it would point us towards a root cause and a solution.
1) We started by presenting velocity data:
The chart shows our planned (blue) and achieved (red) velocity over the last 10 sprints.