Term Definition: timeboxing

The approach to the management of an iteration's schedule recommended in the RUP: having initially established the scope and schedule for an iteration, the project manager is encouraged to actively manage that scope (and the resources committed to the iteration) so as to meet the planned iteration end date, rather than slipping the end date to accommodate the originally planned scope, if development takes longer than planned. In the RUP, reduction of scope is preferred to addition of resources to manage a slipping schedule. The motivations for this approach are to make the results of an iteration visible to the stakeholders and to assess the iteration, so that the lessons learned may be applied to subsequent iterations.