What are The Components of the Milestones?

I agree with Alex.

However, I would use the word 'elements' of a milestone. "Components" have a specific other meaning in the context of milestones.

Milestones help you coordinate work across teams to deliver the right work at the right time, and let you see how work is unfolding in alignment with a key market deadline. Milestones also give executives and other stakeholders immediate, realtime visibility into your progress toward your business priorities.

Milestone literally refers to a roadside marker that lists the distance to a particular location. These days, the word is more often used figuratively to refer to significant events in life, like graduating from college or getting married. It acts sort of like the road sign: it's often a moment when you reflect on where you stand in life. A milestone can also be a nonpersonal event that results in a big change, such as a milestone victory or a company's sales milestone.

So in a Project a Milestone is as mr. Al-Yazoeri named them, I add for a Project :

Preliminary Design

Final design

Filing for the permits

Tender specifications

shop drawings 

• The milestone name.
• The percent complete of the milestone.
• The planned start.
• The planned finish.
• The actual start.
• The actual finish.

Different parameters set for each of  the Milestone.     If it is construction the milestone could be One third completion; Half completion, three fourth completion, and  the total completion. This is as per our expectations at the beginning about the completion of a project.  Agree with your answer.

Thanks for invitation 

agreed with the answers given by members

i'am agree with the expert mr alexfor their answers

Experts enough answers

Greetings

As milestone is keeping you on the right track, 

then it's components should be all the invested resources used to reach it.

Agreed with colleagues answers

components are Name and Time