Overview of Iteration Planning

Iteration planning is selecting the set of stories to be implemented in an iteration, breaking down the implementation of each story into a set of tasks, and estimating the effort required to accomplish each task.

Prior to planning the first iteration, the development team will establish their velocity, the number of estimated units of ideal time they can accomplish per unit of actual elapsed time. For the first iteration, this will have to be something of a guess, based on past experience. For subsequent iterations, velocity is always equal to the number of units 100% completed in the immediately preceding iteration. This velocity, in combination with the length of the first iteration, will set an upper limit for the combined estimates of the stories selected for the iteration.

The customer or customer team chooses stories for this first iteration, based on what's most important to them. They're constrained, however, by what will fit into the iteration. No matter what, the stories' combined estimates can't exceed the development team's established velocity.

Once the customer has selected stories for the iteration, the development team takes each story, breaks it down into a set of tasks required to implement the story, and estimates the time required for each task. The customer is involved in this activity as well, available to answer the many questions that arise as the team examines the stories in more depth.

The end result of the iteration planning is a detailed activity plan that includes all the tasks to be accomplished to implement the selected stories by the end of our first iteration.