A milestone like " Coding 50% completed " is poorly defined because it is ambiguous and difficult to measure precisely. Here’s a detailed explanation:

Ambiguity : It is unclear what 50% completion means – is it 50% of total lines of code, 50% of modules, or 50% of functionality?

Measurement Challenges : Determining exact percentages of completion can be subjective and inconsistent.

Milestone Criteria : Good milestones should be clear, measurable, and verifiable. " Coding completed for module X " is more specific and measurable.

Project Tracking : Poorly defined milestones can lead to confusion and inaccurate tracking of project progress.