1. A computer-implemented method of performing project schedule forecasting based on stored project data, the method comprising: receiving a first user input selecting a first plurality of work items in a project, respective work items of the first plurality of work items having respective work estimates; receiving a second user input specifying one or more first work item attributes including a first team or a first historical period of time, the one or more first work item attributes referencing historical work completion data associated with the first team or the first historical period of time, wherein the first historical period of time specifies a complete iteration or a complete product release in an agile software development process during which the project and the plurality of work items are being developed; determining, using a statistical metric, a first historical rate of work completion in accordance with the historical work completion data associated with the first team or the first historical period of time, wherein the statistical metric includes at least one of: a first group including an average velocity, a highest velocity, and a lowest velocity previously achieved by the first team, and a second group including an average velocity, a highest velocity, and a lowest velocity previously achieved in the first historical period of time; calculating an estimated time of completion of the first plurality of work items in accordance with the first historical rate of work completion; and providing the estimated time of completion of the first plurality of work items for display.