What do you mean by Gates and Milestones?
Gates and milestones:
Milestones are a completion of main interim objectives for a project for example the key stages of a project through initiation to closure.
Gates are important events or main objectives which have been accomplished at different types of stages of a project. They calculate the key completion or quality of work attained. Gates are minor milestones, but well described in the project management procedure, a firm deliverable which can be realised and accomplished.