An under-appreciated fact: they're not only useful to manage the project.
They're there to protect the project manager too.
If he knows about it.
(thread, 1/N)
Milestones are usually a moment to stop, look at the bigger picture, decide whether to continue, reorganize the team, etc.
For example, by saying "we will release additional budget after the milestone is hit".
With the implicit idea that, this way, they cap the initial investment and thus the downside.
There is the chance that after the milestone is hit, the project gets reorganized and they lose ownership.
- They cap downside (so the project is more likely to get started)
- They get a call option on additional ownership / resources if milestone is hit.
Eg:
- instead of asking directly for a full budget to lead a new project that they personally find promising, skilled project owners ask for an initial smaller budget to reduce downside risk and making the "okay" more likely.
Milestones allow for a project to be ambitious AND have a reduced downside.
- Just asking for a small pilot project carries the risk that, if successful, the full-fledged project will be assigned to someone else. Or that by the time it ends, top management will have changed priorities and it won't confirm additional budget
Milestones are an opportunity to say "I'm here in this role until this goal is reached, then I move on" in a way which guarantees the wish.
Take the time to set them properly, and they will make everything easier.
Neglect them during project setting, and you might bite your hands later.