According to the Agile Alliance, velocity is a measurement of the amount of estimated effort that a team can support in one sprint. Why is velocity important? As Product Managers, we often need to forecast how long it will take to complete a project, or a set of features, so that we can set expectations accordingly. This is where average velocity can be helpful, if measured correctly. Calculating average velocity would seem fairly straightforward but here are some examples of cases in which it is not…

• Case 1: Let’s say that there has been a change in the individual composition of the team – new team members joining or existing team members leaving, or both!
• Case 2: Let’s say that the nature of the work that the team is responsible for changes in a fundamental way (i.e. changes in the technology stack, new project, expanding scope from front-end or middle tier to full stack).

According to the Scrum Alliance, average velocity can be determined by calculating the average of the team’s velocity over the last few sprints, given that the composition of the team and the sprint duration do not change. In each of the above examples, changes have occurred that fundamentally impact the estimated effort associated with stories in the backlog. In such cases, it makes the most sense to recalculate the team’s average velocity once the changes in team composition and nature of the work have stabilized and are somewhat constant.