About Task Duration and Planned Work

Understanding the interaction of certain key task attributes is important for project managers and other users who add tasks to a project schedule. Task type defines what task properties (duration, planned work or resource allocation units) are adjusted when one property is changed.

Planned Work—The number of hours of work required to complete the task. You can manually type a value for Planned Work. If you do not type a value, Planned Work is determined based on the task Duration, Type, and the number of assignees.
Duration—The number of days the task will take to complete. Duration is set to the number of days from Planned Start to Planned Finish. If you manually change Duration, Planned Finish is adjusted accordingly.
Note: A task with a duration of 0 is by definition a milestone task.
Assignees—The workspace members who will work on the task. Adding assignees will impact the task planned work or duration, depending on the Task Type and the hours the assignee can work on the task.
Task Type—The type of task determines how changes to duration, planned work or assignees impacts the task.

The default task type is Fixed Duration (non-effort driven). If you have not changed this when adding a task, this remains the default task type. If you change the type while adding a task, your change remains the default task type until you change it again. For more information, see Task Types Overview.