The Secret of Agile Estimation.

Methodology

In Agile estimation the Fibonacci sequence (1, 2, 3, 5, 8, 13, 21) is used for story pointing. This scale is widely used in Agile as it helps reflect not only the level of effort but also risk and uncertainty. For example when a story is given 13 points, it likely that it needs further grooming and/or needs to be broken apart into smaller stories.

Although it’s easier trying to co-relate story points to actual time (i.e 3 story point stories are done in four days), we should keep in mind that is not always the case. Stories with higher points indicate that higher risk elements are involved such as unfamiliarity with the code base, feature or technology to use or simply because there are interdependencies with other team members. For example let’s compare a bug fix which we consider tricky because we don’t know the root cause or the developer is new to that part of the code meaning that time will be required for investigation and another story for a small size feature also set as a three point story, a feature where the requirements are clear and the developer is familiar with the code base, etc. We should expect that building the small feature will take longer in hours but it has more certaintity and less risk that the bug fix one. However by still pointing the bug fix as a three, everyone in the team including stakeholders can get get a view on the certaintity of geetting this bug fix done based on the story points.