The genius of story points

People have a really hard time wrapping their head around the idea that story points are not related directly to time. They are related to velocity and there’s a real genius in this idea. Let me explain.

Let’s say you estimate based on ideal days. The problem is: how many actual days equal an ideal day? If you’re like most managers there’s a one to one correlation, despite any grounding in reality! You’ve got to calibrate the number of ideal days with reality which is what story points tend to do, but in a slightly different manner – via velocity and the abstract number that comes out of points.

Story points are meant to categorize stories by effort and size. Once you’ve initially categorized your work via story points, you pull in a few stories into your first sprint and then sum up the number of points you think you can do. Once the sprint is complete, you see how many story points you’ve actually completed and that becomes your initial velocity. If you are consistent in estimating story points, you can begin to figure out how many story points you can take in based on velocity.I think the reason story points are so fishy to a number of people is that they’re anchored in velocity, which is something that a new, forming team, doesn’t have yet. Once you’ve completed a few sprints, you’ll have a velocity and a set of canonical stories for each group of story points that you can then hang your hat on.