Project life cycles
What the life cycle is
A project life cycle is the sequence of phases a project passes through from idea to closure. In APM terms the core phases are concept, definition, deployment and transition; the extended life cycle adds benefits realisation after handover. Concept tests whether the idea is worth pursuing (outline business case); definition develops scope, plan and detailed business case; deployment produces the outputs; transition moves them into operational use. Boundaries between phases are decision gates: reviews that answer 'continue, change or stop?' A gate is not a phase and not a quality inspection.
Delivery approaches
Linear life cycles plan once and execute in sequence, suiting stable, well-understood scope. Iterative life cycles deliver in repeated increments and welcome change, suiting uncertain requirements. Hybrid combines both, for example linear governance with iterative development. Candidates must distinguish project, programme and portfolio: a project delivers a defined output, a programme delivers outcomes and benefits through related projects, and a portfolio is the organisation's collection of projects and programmes.
Traps
Common traps: calling transition 'the end' (benefits usually come later); confusing the project life cycle with the product life cycle, which continues through operation and disposal; assuming gates are optional; and thinking a phase ends only when all work is perfect rather than when gate criteria are met.
Worked example
For a website replacement: concept = outline case and options; definition = requirements, design and schedule; deployment = build and test; transition = go-live, training and handover; benefits realisation = reduced support calls measured six months later. Rule of thumb: if a boundary review does not lead to a real decision, it is a progress meeting, not a gate.