Story points represent a measure of the size of the work to implement a Product Backlog item. Rather than indicating a specific duration, like hours or days, story points provide a relative measure of complexity and effort. They encapsulate multiple factors that contribute to the completion of the work, including the actual work to be done, the level of uncertainty associated with the Task, and any potential risks or impediments that might arise along the way.
Story points arose from the challenge of making accurate time-based estimates in software development. Developers found it difficult to predict precisely how long a Task would take, given the variability and unpredictability of the work. However, they could more easily compare tasks’ relative size or complexity. For example, while it might be hard to determine precisely how long two tasks will take, a team could discern that one Task seems about twice the size of another, making story points a more practical and flexible measure.
