Image by Andrew Newbury
Velocity can be a very useful predictor of how much work an agile team will complete in the future. It can be especially helpful when looking forward at least four or five iterations.
This is because over the short term, velocity can vary from iteration to iteration. But, velocity is more stable over the long-term as the law of large numbers kicks in and errors in individual product backlog items are balanced out.
This means velocity can work as a reliable predictor as it allows teams to state things like, “In the next 5 sprints we’ll probably finish between 100 and 120 story points.”
Such statements are based on a team knowing its velocity (perhaps as a single, averaged value but even better as a range).
But how should a team estimate its future velocity when team members are taking time off, whether personally or because of a company holiday?