2.2 Project Life Cycle Phases
Key Takeaways
- A project life cycle is the series of phases a project passes through; phase relationships can be sequential, overlapping (fast-tracking), or iterative
- Cost and staffing start low, peak during execution, and fall sharply during closing — a bell-shaped curve
- Risk/uncertainty and stakeholder influence are HIGHEST at the start and decrease over time; the cost of changes is LOWEST at the start and rises steeply
- A phase gate is an end-of-phase review producing a go / go-with-modifications / hold / kill decision
- Predictive (waterfall) life cycles plan in detail up front; adaptive (agile) life cycles use short iterations and welcome change
The Project Life Cycle
A project life cycle is the series of phases a project passes through from start to finish. Phases give structure: each has a focus, deliverables, and usually a review before the next begins. While industries differ, PMI describes a generic four-phase pattern you should recognize on the exam.
| Generic phase | Primary work | Key deliverables |
|---|---|---|
| Starting the project | Establish purpose, feasibility, high-level scope | Project charter, stakeholder register |
| Organizing and preparing | Build detailed plans and team | Project management plan, WBS, baselines |
| Carrying out the work | Execute the plan, produce deliverables | Deliverables, work performance data |
| Ending the project | Verify, hand off, archive | Final product, lessons learned, sign-off |
Phase Relationships
- Sequential — a phase starts only after the prior phase finishes. Lowest risk, longest duration. Example: regulatory design fully approved before construction begins.
- Overlapping (fast-tracking) — a later phase starts before the prior one finishes to compress the schedule. This raises risk and rework because later work proceeds on incomplete information.
- Iterative/incremental — phases repeat in cycles, each refining the deliverable; common in adaptive (agile) work.
Trap: Fast-tracking (overlapping phases or activities) is often confused with crashing (adding resources to shorten duration). Fast-tracking adds risk, not cost; crashing adds cost, not necessarily risk.
Phase Gates
A phase gate is a review held at the end of a phase to decide whether the project should proceed. PMI also calls these stage gates, kill points, decision points, phase reviews, or toll gates. The reviewer (often a sponsor or governance board) chooses one of these outcomes:
| Decision | Meaning |
|---|---|
| Go | Proceed to the next phase as planned |
| Go with modifications | Proceed after adjusting scope, budget, or schedule |
| Hold | Stay in the current phase for more analysis or rework |
| Kill / terminate | End the project; sunk costs are not a reason to continue |
How Project Variables Change Over the Life Cycle
This is the most heavily tested life-cycle concept. Commit the four curves to memory:
- Cost and staffing — start low, build through planning, peak during execution, then drop sharply in closing (a bell curve).
- Risk and uncertainty — highest at the start (most unknowns) and decline as decisions are locked in and work is completed.
- Stakeholder influence over the product — highest at the start, declining as decisions are made and become costly to reverse.
- Cost of making changes — lowest at the start, rising steeply as work is built; a change in execution costs far more than the same change in planning.
Critical relationship: Stakeholder influence and the cost of changes are inversely related. Early on, stakeholders have maximum influence and changes are cheap; late in the project, changes are expensive and influence is low. CAPM questions love this inverse pairing.
A quick worked scenario: a sponsor wants to add a feature. If the team is still in planning, scope is updated at low cost. If the team is mid-build, the change triggers rework, retesting, and schedule impact — sometimes 10x the planning-stage cost. The principle (cost of change rises over time) is what the exam is testing, not a specific multiplier.
Predictive vs. Adaptive Life Cycles
The CAPM allocates 17% to Predictive Methodologies and 20% to Agile Frameworks, so this contrast is essential. A predictive (waterfall) life cycle defines scope, schedule, and cost early and controls change formally. An adaptive (agile) life cycle delivers in short iterations, refining requirements continuously and welcoming change. A hybrid blends both.
| Characteristic | Predictive | Adaptive (Agile) |
|---|---|---|
| Planning | Detailed up front | Progressive, just-in-time |
| Requirements | Fixed early, stable | Evolving, refined each iteration |
| Delivery | Single delivery near the end | Incremental, frequent |
| Change | Controlled via formal change process | Expected and welcomed |
| Feedback | At phase gates | Continuous, each iteration |
| Best for | Well-understood, low-change work | High-uncertainty, evolving needs |
Rule of thumb for scenario items: stable, well-defined requirements → predictive; high uncertainty or rapidly changing needs → adaptive.
The Development Approach Continuum
The CAPM tests a spectrum of development approaches, not a binary. From most plan-driven to most change-driven:
| Approach | Requirements | Delivery cadence | When to use |
|---|---|---|---|
| Predictive | Fixed early | One delivery at the end | Requirements clear and stable |
| Iterative | Refined through repeated cycles | One delivery, improved each cycle | Requirements known but solution unclear |
| Incremental | Defined in slices | Many usable increments | Value needed early and often |
| Adaptive (Agile) | Evolve continuously | Frequent increments + iteration | High change and uncertainty |
| Hybrid | Mix of fixed and evolving | Mix | Different components need different handling |
Iterative improves one deliverable through repeated passes (refining a prototype); incremental builds the deliverable in usable pieces (ship feature 1, then 2). Agile combines both.
Phases vs. the Life Cycle vs. Cadence
Keep three terms distinct on the exam. A phase is a collection of logically related activities ending in one or more deliverables. The life cycle is the full series of phases. Delivery cadence is how often you release value (single, multiple, or periodic). A predictive life cycle usually has phases like requirements, design, build, test, deploy — with a single delivery cadence. An adaptive life cycle has short repeating iterations with a periodic delivery cadence. CAPM scenario items frequently combine these terms, so read carefully whether a question asks about phase structure, the overall life cycle, or how often value ships.
Trap: "Predictive" is not a synonym for "sequential phases." A predictive project can still overlap phases via fast-tracking. The predictive/adaptive distinction is about how requirements and change are handled, while the sequential/overlapping/iterative distinction is about how phases relate in time. Do not collapse the two axes.
At what point in a project are risk and uncertainty typically HIGHEST, and the cost of changes LOWEST?
A team starts the construction phase before design is fully complete to shorten the overall schedule, accepting added risk of rework. This technique is called:
A project has rapidly changing requirements and frequent stakeholder feedback, with value delivered in short increments. Which life cycle fits best?