I have been a strong advocate over the years of using Story Points to track team velocity. In spite of many of the self-inflicted problems teams face when using Story Points (e.g., trying to initially assign some measure of time to a Story Point, or trying to normalize Story Points across teams, or confusing Story Points and task-hours, etc.), when used correctly, Story Points (and the velocity calculations they enable) make project tracking and projection incredibly easy and relatively accurate as well. (As a side note, check out the following article by Jeff Sutherland: link.)
What I’d like to cover in this posting is that using Story Points is not the only way to track a team’s velocity. For teams that have been writing User Stories for a while, and who have gotten good at breaking their work down into small enough chunks such that one or more stories can be completed (“Done!”) in an iteration, I would like to recommend that they forego the effort of sizing User Stories with Story Points. They’ve already shown that they know how to start with an Epic, and break an Epic down into User Stories that can be completed in an iteration. Thus, they’ve demonstrated that they have a relative amount of uniformity in the way that they come up with their backlog of User Stories – their stories are all in the same range regarding the amount of time and effort required to complete each one of them.
With that in mind, such teams could simply measure velocity based on completed User Stories – the principle is the same as Story Points, but mature teams can fore-go the effort required to size each User Story with Story Points (e.g., through Planning Poker).
Let me give a couple of examples – the first one using Story Points. Team A has 50 Story Point’s worth of User Stories on its backlog, and they’ve demonstrated over the course of time that they can generally complete about 10 Story Point’s worth of stories in an iteration (velocity = 10). In order to determine how long it will take to complete the remaining stories, it’s easy to divide 50 by 10 and come up with an estimate of around 5 iterations. If a customer is asking how long before the team can get to a feature that the customer is interested in, and the User Story associated with that feature appears about 30 points down the rank-ordered backlog of stories, then the team can tell the customer that it will be about 3 iterations (30 divided by 10).
The second example is that Team B has 10 stories on its backlog and they’ve demonstrated that they typically complete about 2 User Stories every iteration (velocity = 2). To determine how long it will take to complete the remaining stories, divide 10 by 2 and come up with an estimate of 5 iterations. If a customer is asking how long before the team can get to a feature that the customer is interested in, and the User Story associated with that feature appears about 6 stories down the rank-ordered backlog of stories, then the team can tell the customer that it will be about 3 iterations (6 divided by 2).
If you’re part of a fairly experienced team, and if your team already has an established velocity, consider trying this approach in lieu of assigning Story Points – it can help save some time by not going through the sizing exercises. However, if your team is fairly new to writing and sizing User Stories, or if your team doesn’t yet have an established velocity, I would recommend sticking with Story Points for now because the process of assigning Story Points (during a Planning Poker exercise, for example) is *very* helpful in aligning a team’s thinking, as well as building team synergy, as the team goes through the process of having the discussions that naturally arise when sizing stories.
As always, please feel free to comment, provide suggestions and recommendations, or even tell us about your experiences using Story Points and/or other ways of tracking velocity. Thanks!