When to split a project into phases
Not every project needs phased delivery. Here's how to recognise when splitting work into phases helps - and when it just adds overhead.
Some projects unfold naturally in one continuous push. Others need deliberate phase gates to stay sane. The difference isn’t always obvious upfront, and getting it wrong creates either unnecessary bureaucracy or a project that slowly drifts into chaos.
The instinct to phase everything comes from good intentions-breaking work into manageable chunks, creating natural checkpoints, giving stakeholders visibility. But phasing has real costs: handoff friction, momentum loss, the overhead of treating each phase as its own mini-project. The question isn’t whether phased delivery is ‘best practice.’ It’s whether it’s right for this project.
The signals that demand phases
Phasing makes sense when the project has genuine dependencies on external validation or decisions that literally cannot be made until earlier work is complete.
The clearest case: you cannot proceed without feedback from work that hasn’t happened yet. A product redesign where user testing will reshape the next iteration-you’re not guessing what users want, you’re waiting to see them struggle with version one. A software build where you need real performance data before committing to the architecture. Construction projects where each phase requires inspection sign-off before the next can begin legally.
Another signal: stakeholder commitment is shaky. If you’re dealing with a client or executive sponsor who hasn’t fully bought in, phased delivery lets you demonstrate value before asking for the next tranche of budget or political capital. You’re de-risking their decision by giving them off-ramps. I’ve seen a $400K project get approved only because we structured it as four $100K phases-the CFO would never have signed off on the full amount upfront, but she’d commit to phase one.
The third signal is team availability. If your core contributors aren’t available continuously-shared across projects, or specialists needed only for specific portions-phases give you natural boundaries to plan around. Trying to run a continuous project with intermittent staffing creates scheduling nightmares and half-context handoffs.
Finally: regulatory or compliance gates. Healthcare, finance, government contracting-some industries require formal phase sign-offs. You don’t get to skip them because your project flow would be smoother.
When phasing creates more problems than it solves
The trouble starts when people phase projects for administrative tidiness rather than genuine project logic.
I watched a team split a twelve-week project into four three-week phases purely because their PMO wanted quarterly reporting alignment. The phases had no meaningful dependencies-work could have flowed continuously. Instead, each ‘phase transition’ created a week of status reports, retrospectives, and re-planning ceremonies. The project took fourteen weeks. Two weeks of pure overhead, roughly 15% of the timeline, burned on ceremony.
Phasing also fails when the phases are artificial. ‘Phase 1: Research. Phase 2: Design. Phase 3: Build.’ This sounds logical but rarely matches reality. Real work doesn’t move cleanly from research to design to build. You learn things during build that send you back to design. You discover during design that you needed different research. Rigid phase gates turn natural iteration into bureaucratic exception handling-change requests, scope amendments, steering committee approvals just to do the obvious thing.
Small teams get hit hardest by unnecessary phasing. When you’re running a project with three or four people, the overhead of formal phase transitions-the documentation, the sign-offs, the ‘phase kickoff’ meetings-can consume 20% of your actual working time. I’ve seen two-person teams spend more hours on phase transition paperwork than on the work the phase was supposed to deliver.
A better mental model
Instead of defaulting to phases, ask: what decisions need to be locked before other work can proceed?
Some projects have genuine decision points where you need to stop, evaluate, and potentially change direction. These are natural phase boundaries. Other projects have decisions that can be made incrementally, as information emerges. These work better as continuous delivery with informal checkpoints.
The key question: ‘If we learn something unexpected halfway through, how hard is it to adjust?’ If adjustment is relatively easy-you’re building something modular, or your scope has natural flexibility-continuous delivery wins. If adjustment is expensive or impossible-you’re committing to infrastructure that’s hard to change, or making irreversible decisions-phases give you deliberate pause points to confirm you’re still heading the right direction.
Emergency departments triage this way instinctively. A patient presenting with unclear symptoms doesn’t get a full treatment plan on arrival. They get a diagnostic phase-tests, observation-and only then does treatment begin, informed by what the diagnostics revealed. But a patient with a clear, simple presentation goes straight to treatment. Phasing the straightforward case would just delay care.
The parallel for projects: complexity and uncertainty warrant phases. Clarity and predictability don’t.
Making the call
Before you split a project into phases, answer these honestly:
- Are there decisions that genuinely cannot be made until earlier work is complete? - Is stakeholder buy-in uncertain enough that you need intermediate proof points? - Will team availability force natural breaks anyway? - Are there external gates-regulatory, contractual, technical-that require formal transitions?
If you’re answering ‘no’ to all of these, you don’t need formal phases. You need good progress tracking and regular check-ins, but not the overhead of treating each chunk as a separate project.
If you’re answering ‘yes’ to one or more, design your phases around those specific constraints. Don’t default to the generic ‘discovery, design, delivery’ template unless it actually matches your project’s natural rhythm.
The goal is to structure work around how it actually flows, not how a textbook says it should. Sometimes that means phases. More often than project managers want to admit, it means something simpler.
Phased delivery is a tool. Using it when you don’t need it just slows you down.
Quick reference
Phase gates: Formal checkpoints between project phases where work must be reviewed and approved before moving to the next stage.
Stakeholder: Any person or group with an interest in or influence over a project, such as clients, executives, or team members.
PMO: Project Management Office - a centralized department that sets project management standards and processes for an organization.
Continuous delivery: An approach where work flows steadily without formal phase breaks, with regular releases or checkpoints rather than distinct project stages.
Scope: The defined boundaries of what a project will and will not deliver, including features, functions, and deliverables.
Triage: The process of quickly assessing and prioritizing items (or in this case, patients) to determine the order and type of action needed.