As the name Agile suggests it is all about embracing change and being able to deliver quickly. The most important thing in Agile is to understand the estimation methodology. Development teams working on Agile are directly responsible for estimating their work in terms of Story points. Now let us see in detail about story points. Usually, the story points must be following Fibonacci series (1,2,3,5,8,13…). Story point is the unit of work that is estimated by the individual team member who is going to work on a particular story for a particular iteration/Sprint. While estimating the story points the Scrum Master must ensure that the team members pick a story point that they are comfortable with. For example, David can run 10 miles in say 2 hrs. However, Dan, his friend says that he can cover the same 10 miles in 1 hr. As you can see the velocity that is estimated by 2 individuals could be quite different and it is only natural to be that way. So, when a team member picks story points it indicates the effort required to complete that story. At the start of the Agile project since the velocity is not well established some thumb rules we could follow as below:

Please remember that the story points picked by a team member is not indicative of his/her skill levels or competence in a direct way. Rather the story points would even out as the team progresses and indicate the overall velocity of the team in completing “x” number story points within the Sprint cycle.

The most important point to understand is that the estimation in Agile must be owned by each individual team member working on the story rather than being driven by Product Owner/Scrum Master. Also, the estimation indicates the overall velocity of the team that would stabilize over the long run once the team comes up the learning curve.