Need to understand about Milestone in PPM
The PPM User Guide probably says it best, as a starting point for you to understand its function and use…
“Milestones are also a type of gate. In many different project methodologies the milestone is the only gate type. In phase-gate methodologies, milestones are typically used to mark significant points in the project that can trigger other activities.
The default milestone gate in Agile is the “Milestone” sub-class.
Typically milestones are not sub-classed. However, if your process has milestones that are important to you as a metric or that are needed to measure progress across the portfolio, it is recommended that you add sub-classes to meet that need. Examples would be MM1, MM2, or MS1, MS2.
Workflows are not typically used for milestones. However, using scripting and events, you could trigger a notification to mark the passing of a milestone. For example, when a customer project reaches a milestone, a notification is sent to accounting to bill the customer for work completed.”
We have used notifications and other means in the past for Milestones in projects when the project plan reaches these gates. A milestone is just that – a point of important reference or status in a project where some action or additional process or activity must be addressed.