The period of time between the project moving from a simple collection of ideas in a client requirements definition to a finished entity that meets all its originally agreed requirements. Often defined within a methodology, it can be summarized into four basic headings:

• Startup

• Plan

• Do

• Review

As the majority of measurable work is contained within the 'Do' stage, this is where the majority of the project's costs will come from and where the majority of the project's risks will be found.

SOURCE: microsoft project