A milestone represents any significant event, goal, or gate in a project. Although P6 considers them a type of activity, milestones have zero duration; at any given moment they are either achieved or not. Some examples of milestones in an office building addition project might include the following:
- project definition complete
- structure complete
- end bidding process
Milestones can also be assigned at the WBS-level, and each one given a weight which indicates its importance to the project schedule. When you mark a milestone as complete, the weight is used to calculate the performance percent complete of all activities included in the WBS level.
During project planning, you will want to identify the major milestones as they will help you monitor the project's progress. You can also assign an activity owner or a primary resource to a milestone.