Tasks

A task is a work item that tracks a combination of three elements: duration, work, and units. Duration defines the total length of time required to complete a given task, measured by a task's start and finish dates. Work defines the total amount of labor that is needed to complete a given task. Units defines the resource (or resources) assigned to complete a given task.

All tasks are scheduled using the formula Duration = Work / Units. You can determine which part of the formula is calculated (or recalculated) by choosing a task type:

Fixed Duration A task where the values for the task's start and finish dates are fixed values. Changes to a task's units or work will not affect fixed duration. For a task with a fixed duration task type, work will be recalculated when units or duration values are revised and units will be recalculated when work is revised.
Fixed Work A task where the value for the work to be completed is a fixed value. Changes to a task's units or duration values will not affect fixed work. For a task with a fixed work task type, duration will be recalculated when units or work values are revised and units will be recalculated when duration is revised.
Fixed Units Default. A task where the value for the resource (or resources) assigned to the task is a fixed value. Changes to a task's work or duration values will not affect fixed units. For a task with a fixed units task type, duration will be recalculated when units or work values are revised and work will be recalculated when duration is revised.

In addition to duration, work, and units, many tasks also have dependencies and constraints. Some tasks are summary tasks, which contain rolled-up information from all of the child tasks.