Metrics are an important part of Agile project management approaches like Scrum. One of the most used measures to estimate the amount of work are the story points. In this small article, Pedro Gustavo Torres explains what they are, why you need them and how to use them.
Pedro Gustavo Torres provides many definitions of story points. One of them is “a unitless measure of magnitude for work yet to be done, based on relative sizing.” He explains also why you should use story points based on the difference between accuracy and precision. He wrote “Accuracy and precision are not the same thing. Precision is a lot more expensive. Precision is always desired, but accuracy creates more value. However, story points provide sufficient accuracy when working in nondeterministic systems.” It is very difficult to create a precise time estimate. Story points provide an estimate that is accurate enough to define the effort that should be included in Scrum sprints. With historical data, the team can assess the relationship between time and points. However, story points cannot be related to a specific duration, but rather with a duration interval.
Read the complete blog post on https://www.scrumalliance.org/community/articles/2016/february/story-points-explained-the-what-why-and-how