Waterfall methodology is a linear, sequential approach to managing projects in which progress flows in a single direction, like a waterfall.
It is often used by project managers in software development and other technical fields, but as you’ll learn in this article, waterfall can be employed on nearly any project.
Phases Of Waterfall Methodology
The waterfall process typically consists of several distinct phases. An example of waterfall phases might look like:
- Requirements gathering and analysis
- Design
- Implementation or construction
- Testing and quality assurance
- Deployment and maintenance
Each phase must be completed in its entirety before the next one can begin, and there is little overlap or iteration between phases.
The process is heavily reliant on detailed documentation and planning, and changes to the project scope are often difficult to incorporate once a phase has been completed.
When To Use Waterfall Methodology vs. Agile
Waterfall methodology is most suitable for projects where the requirements are well understood and don’t change much, and the product is clearly defined.
Consider waterfall when your project:
- Has well-defined, clear and non-changing requirements
- Has a well-defined and clear product or outcome
- Has a specific schedule and budget
- Has a defined process that can be followed
- Has a predictable outcome
Waterfall methodology works best for projects that have a clear beginning and end, with a defined scope and deliverables that can be planned and executed in a linear and sequential manner.
It is also suitable for projects where the requirements are well understood and don’t change much, and the product is clearly defined.
It’s less suitable for projects that are difficult to specify in advance, have a lot of unknowns, or are likely to change a lot over time.
In those cases, Agile is likely a much more effective approach.
Agile focuses on delivering small, incremental changes to the product through rapid iterations and regular feedback from stakeholders.
It is more flexible and adaptive to change, and it is better suited for projects where the outcome is not entirely predictable.
Determining whether to use waterfall or agile should come down to the specific characteristics of the project, the needs of the stakeholders, and the project team’s skillset.
When Waterfall Actually Works
There’s a tendency in some circles — particularly the ones bathed in Agile terminology and drowning in standups — to treat Waterfall like it’s a relic. Something outdated. A method to be quietly ignored.
But the reality is, Waterfall still works.
Not in every context, sure. But when the stars align (and the scope is crystal clear), it delivers.
Waterfall earns its stripes in environments where change is expensive.
Think construction projects, manufacturing pipelines, aerospace systems, or anything that has to tiptoe through legal, regulatory, or compliance-heavy minefields.
When you’re building a bridge, no one wants to iterate on where the supports go once the concrete’s poured. You plan, sequence, execute — in that order.
Another sweet spot? Fixed-scope software projects where requirements don’t just sit still — they’re engraved in granite.
Enterprise deployments that have to align across departments (each with their own calendar, budget, and egos) often need the kind of top-down scheduling and upfront design that Waterfall demands.
It’s less about velocity — more about predictability.
And that’s the real strength hiding under Waterfall’s starchy collar: predictability.
Done well, it gives stakeholders a sense of clarity; a schedule that doesn’t morph every sprint; a budget that doesn’t balloon every week.
For the right kind of project — one with few surprises and even fewer tolerance for improvisation — Waterfall isn’t a museum piece. It’s a blueprint.
Waterfall vs. Agile: Stop Treating It Like a Cage Match
Somewhere along the line, Waterfall and Agile got turned into rivals in a zero-sum game — like two project management philosophies enter, one leaves.
The debate’s been fed by blog posts, boardroom turf wars, and more than a few project retros that turned into therapy sessions.
But what if we called a truce?
The truth is, not every project fits neatly inside a single methodology. In the real world — the messy, contradictory, resource-constrained world — hybrid approaches are more common than purists like to admit.
You might plan your project in phases, like Waterfall demands, but run your development teams using Scrum.
Or maybe your organization needs to report progress through traditional milestones for funding, even though the teams themselves are working in Kanban-style flows.
They even have a name for this unholy union: Water-Scrum-Fall.
Clunky? Yes.
Practical? Also yes.
The point isn’t to pick a side and defend it with buzzwords. It’s to design your process to reflect the realities of your work — your team’s strengths, your stakeholders’ expectations, and the constraints that refuse to go away no matter how Agile you claim to be.
Sometimes that means wrapping iterative processes inside a larger fixed structure.
Other times it means starting with a Waterfall base and injecting flexibility where it matters most — maybe at the feature level, maybe in how you handle change requests.
Treating Agile and Waterfall like they’re locked in mortal combat misses the nuance entirely.
You don’t need to be in one camp or the other.
You just need to know what works — and when to switch lanes.