I came across this post by Michael Norton and thought I would reference it here: Stabilising Velocity Michael makes some keen observations on both causes and effects of unstable velocity.
Predictable velocity is a key agile planning metric. There is an implicit assumption in agile planning that this iterations velocity will be similar to the last iteration. Without this predicability it is very difficult, if not impossible, to provide and sort of forecast.
Trying to identify the root causes of unstable velocity is difficult. Quite often there are layer upon layer of symptoms masking or hiding the real cause. I delving into root causes I find these techniques useful
- Value Stream Analysis – helps identify waste: time waiting for some dependency.
- The 5 Why's – for finding the root cause
- Story dependency analysis
- Cause and effect diagramming </ul>