What are Project Milestones? Meaning and definition

Historically a milestone was a stone marker for a mile on a route. Today a milestone refers to a significant marker or point, for example it might be an achievement or an important date or an important point in project or initiative. stakeholdermap.com

Milestones in Project Management

In Project Management milestones are key points in a project lifecycle. They might be target dates that must be met or delivery of important work packages or markers of progress - the completion of a phase or stage. stakeholdermap.com
Milestones shown on a project lifcycle
In project schedules specific symbols are used to denote a milestone. For example, in Microsoft Project a diamond shape is typically used.

Typical Milestones in a Project

Milestones are an important way to measure progress (time and cost) and create a sense of urgency. Typical milestones in project management could be:
  • Kick off or launch
  • PID sign-off
  • Feasibility start/finish
  • Design completion
  • Sprint start and end dates
  • Completion of each phase e.g. initiation, testing etc
  • Completion of testing
  • Prototype release date
  • Start of a code freeze
  • Financial period end/start e.g. half year, quarter
  • Start of a busy period e.g. run up to thanks giving, term time
  • Go Live or product launch
  • General Availabity e.g. of a software release
  • A fixed event date e.g. Olympics start
  • A deadline on the Critical Path
  • An audit date
  • etc...
As you can see what is considered a milestone will vary between projects, industries, sectors, methodologies, and organizations. The key point is that all project will have milestones and these must be defined in product documentation, and captured in schedules and monitored in progress reporting.

If you are not sure what the milestones are on your project (there will always be some) check the list above or the mind map shown below for potential sources of Project Milestones.

Get a Milestone List Template

Sources of Project Milestones

Where & when are milestones defined?

Milestones may form part of a contract payments terms. It is not uncommon for professional services statements of work to include a payment plan based on the completion of pre-agreed milestones.

During the start up or initiation phase of a project, milestones will be identified and documented. The PID and Project Brief should define these key dates and deliverables for the project. The work breakdown structure will also reveal key work packages that will mark significant points in project progress.

Dennis Lock notes that ideally milestones will align with the WBS:
Ideally, milestones should coincide with the completion of packages from the work breakdown structure (Lock, 2007).
This alignment with work packages helps with a common cost reporting method in which milestones are plotted against project costs and time to produce time-scaled budgets.
Once identified, milestones should be reflected in the project schedule and will form an important way to monitor and report on project progress. Most planning software, like Microsoft project, allows the schedule to be filtered and reported on so that progress against milestones can be shown. This is particularly useful for senior management and the Project Board.

Project milestones - references

Dennis Lock, 2007. Project Management , 9th ed. Aldershot:Gower Publishing Limited. Latest edition Project Management from Amazon.

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