Timebox

In Project management, a timebox is a period of time in which to accomplish some task. The end date is set in stone and may not be changed. If the team exceeds the date, the work is considered a failure and is cancelled or rescheduled. Some timeboxes allow the team to adjust the scope of the task in order to meet the deadline.

Timeboxes are used as a form of risk management for tasks that easily run over their deadlines. Timeboxes are commonly used in agile software development to manage software development risk. In agile development, the team is repeatedly tasked with producing a releasable improvement to software, timeboxed to a specific number of weeks.

When considering the traditional triple constraints of Project management (time, cost and scope) the time and cost constraints are fixed in this type of project contracting, but the scope (requirements) constraint is not. Therefore, timeboxing is the favorable type of contracting for projects in which the deadline is the most critical aspect and when not all requirements are completely specified upfront. A lack of detailed specifications typically is the result of a lack of time, or the lack of knowledge of the desired end result (solution). In many types of projects, and especially in software engineering, analyzing and defining all requirements and specifications before the start of the realization phase is impossible.

The advantages of timeboxing over working with more traditional methods - in which there is a need to specify all details and features upfront - are that work can be started on the actual solution, or product, sooner, because less requirements and specifications gathering is necessary upfront. There is also a better structure for allowing for new insights that are developed during the project to be reflected in the end result.