Project Lifecycle is a term which depicts a project through conception to maturity, and on to fruition. It is a convenient enough metaphor which can be easily applied to project management.
Fruition, in this context, consists of the planned outputs and the seeds of knowledge and experience gained which should result in better, more robust offspring, i.e., future projects will benefit from the lessons learned from their forebears.
We assign rules and gateways to the project as it develops and these decision points are where progress is evaluated and further investment reviewed.
Another use of the Lifecycle is to break down the project into convenient administrative phases which can greatly assist with resource planning - just as a child's demands change as it grows, so a project's requirements vary as it moves through its development stages.
Finally, the project Lifecycle allows us to recognize that each project will end and that this event should be planned and managed.
Project Lifecycle is a descriptive term used to help us visualize the finite nature of projects and keep their beginning, middle, and end, in perspective.
As a project moves through its Lifecycle so its requirements evolve and its viability can be assessed.
The term Lifecycle reminds us also that each generation of projects should lead to improvements in the next.