Understanding Activity Milestones

A milestone represents any significant event, goal, or gate in a project. Although they are considered a type of activity, milestones have zero duration. A project might have met an activity milestone, or it might still be progressing toward one.

Some examples of milestones in an office building addition project might include the following:

During project planning, you will want to identify the major milestones to help you monitor the project's progress. You can also assign an activity owner or a primary resource to a milestone. When you mark a milestone as complete, the weight is used to calculate the performance percent complete of all activities

Even though milestones have no duration, you can include milestone Start and Finish dates when doing activity and WBS summary calculations and rollup bands. You can also enter Start and Finish date information when filtering by important dates, and during schedule health checks, to ensure your project schedule is progressing as planned.

Milestones can still be considered in calculations and rollups even if only one date is available. For example, if a WBS has a Start date designated as a milestone, but a Finish date is unknown, the system will infer that the Finish date is the latest Start date in rollups and summary calculations. If a WBS only has Finish milestones, the system will use its Earliest Finish date as its Start date.