formulate requirements here (together with your adviser)
Milestones and Planning
A milestone is a scheduled event signifying the completion of a major deliverable or a set of related deliverables.
A milestone has zero duration and no effort -- there is no work associated with a milestone. It is a flag in the workplan to signify some other work has completed.
Usually a milestone is used as a project checkpoint to validate how the project is progressing and revalidate work.
(Source: http://www.mariosalexandrou.com/definition/milestone.asp)
[1] K. Charmaz, Constructing grounded theory. Introducing qualitative methods, Los Angeles and London and New Delhi and Singapore and Washington DC: SAGE, 2nd edition ed., 2014. [2]