Project Management guide · Project management fundamentals
What Is Waterfall Project Management? Phases, Pros and Cons
Waterfall is a predictive approach in which a project moves through a fixed sequence of phases, each completed before the next begins. Like water flowing downhill, progress is meant to move in one direction.
Key takeaways
- Waterfall moves through sequential phases with a detailed up-front plan.
- It suits stable, regulated or indivisible projects.
- Its main weakness is late feedback.
The Waterfall phases
- Requirements: gather and document everything the solution must do.
- Design: plan the architecture and detailed design.
- Implementation: build the solution.
- Verification: test it against requirements.
- Deployment: release to users.
- Maintenance: support and fix after release.
In 1970, Winston Royce described this sequence in a paper on managing large software projects, while also cautioning that a purely sequential process is risky.
Advantages
- Clear structure and milestones.
- Detailed documentation.
- Easy to understand and to estimate when requirements are stable.
- Fits contracts and regulation that require approved phases.
Disadvantages
- Late feedback: users see results only at the end.
- Changes are costly once a phase is complete.
- Risks such as misunderstood requirements are found late.
- Testing is squeezed when earlier phases overrun.
When to use Waterfall
- Requirements are stable and fully understood.
- The result has value only when complete.
- The work is regulated and must follow approved stages.
- The team has done similar projects before.
Compare with Agile in Agile vs Waterfall.
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Frequently asked questions
Is Waterfall outdated?
No. It remains the right choice for stable, regulated or physical projects.
What is the V-model in Waterfall project management?
A variant of Waterfall that pairs each development phase with a corresponding testing phase.
What is Waterfall project management?
A sequential approach in which a project moves through phases such as requirements, design, build, test and deployment, with each phase usually completed before the next starts.
What are the phases of Waterfall?
Requirements, design, implementation, verification, deployment and maintenance.
Who created the Waterfall model?
Winston Royce described the sequence in a 1970 paper, though he warned that a purely sequential process is risky. The name Waterfall was applied later.
What are the advantages of Waterfall?
Clear structure and milestones, detailed documentation, easier estimation when requirements are stable and a good fit for contracts and regulation.
What are the disadvantages of Waterfall?
Late feedback, costly changes after a phase is complete, risks found late and testing squeezed when earlier phases overrun.
When should you use Waterfall?
When requirements are stable and understood, the result only has value when complete, the work is regulated or the team has done similar projects before.
Is Waterfall the same as predictive project management?
Broadly yes. Predictive is the wider term for approaches that plan scope, schedule and cost up front; Waterfall is its classic form.
Can Waterfall and Agile be combined?
Yes. Hybrid approaches use Waterfall-style governance and milestones with Agile delivery inside them.
Do Waterfall projects use Gantt charts?
Yes. Gantt charts are a common way to show the sequence and timing of Waterfall tasks and phases.