What Is Waterfall Project Management? Phases, Benefits, & Uses
Waterfall 101: The waterfall methodology is a linear way to manage projects that involves distinct phases. Each phase relies on the completion of the previous one, and only one phase is active at a time.
A Phase-Based Approach: Waterfall consists of six phases: requirements gathering, design, implementation, testing, deployment, and maintenance, which correspond with the project life cycle.
The Role of Software: Project management software is the best way to manage waterfall projects (or projects following any method, for that matter). It's the easiest way to keep projects on time, on scope, and within budget.
Waterfall project management is a linear methodology that involves completing planning and meetings upfront to determine project scope, requirements, and risks.
It's the right method for your project if your requirements are specific and fixed, previous stages need to be completed before future ones can begin, and changes or revisions after the project has started are limited. Here's how waterfall project management works.
What Is Waterfall Project Management?
Waterfall project management is a linear project management methodology that moves through distinct phases of work. The next phase of work is dependent on the previous phase, so only one project phase can be worked on at a time.
The project plan in a waterfall project is mapped out in great detail, with milestones along the way from project initiation to project closure.
The 6 Phases of Waterfall Project Management
When you use waterfall, your project goes through six sequential phases. You'll use the project life cycle in conjunction—the steps below overlap with the five phases of project initiation, planning, execution, monitoring and controlling, and closure.
1. Requirements Gathering
In the first step of the waterfall methodology, you'll gather all of the project requirements. This involves talking to your stakeholders and your team, reviewing the project charter and any other scope documents, and outlining specific deliverables and activities.
You'll gather four types of requirements: functional requirements, technical requirements, non-functional requirements, and system requirements. Then, you'll write your requirements document (alongside your project plan). You'll need to update this if requirements change during the project.
Review this document with your project team before kicking off the work, and make sure to get buy-in from any external stakeholders or clients as well (this is often done during the project kickoff).
2. Design
In this step, your project team will begin designing solutions based on the requirements. Assign deliverables to team members based on their availability and skillset (using project management software). The exact deliverables will depend on the type of project you're working on (e.g. for a website project, the team should deliver wireframes and webpage designs).
As the project manager, in this stage you'll be reviewing and providing feedback on the deliverables, managing the project timeline and due dates, and keeping an eye on the critical path to make sure the project stays on track to meet the deadline.
Once designs are approved by stakeholders or clients, you can move on.
3. Implementation
In the implementation phase, the development team implements the designs created in the previous stage. Once again, as the project manager, you'll be keeping an eye on the timeline and assigning tasks. You'll also need to monitor the project for potential risks and dependencies that could arise and to make sure budget isn't being used up too quickly.
The deliverables for the development process will again depend on your project type. For our website project example, deliverables will include working web pages (likely in a staging or non-live environment first to allow for quality assurance).
In this phase, you might discover that something created in the design phase isn't technically possible, which might require you to go back to the previous stage and rework the designs (which will cost you time). You can mitigate this by having the software development team involved in reviewing designs.
4. Testing & Quality Assurance
In this phase, you and your team will test and review the quality of what's been delivered to make sure it meets requirements and stakeholder expectations.
The project team takes care of this, but if you as the project manager have a technical background, you might be involved as well. You'll need to write test cases, document issues or bugs that need to be fixed, assess deliverables according to quality metrics (which should be outlined in the requirements gathering phase), and account for all use cases.
You might need to send the project back to your developers to fix any major bugs or issues that you discover in this process. This is why it's important to build extra time into your project for the testing phase—you don't want to get held up fixing bugs at the last minute.
5. Deployment
Once the team has fixed all bugs and issues that were found during the quality assurance workflow, the team can deploy the project. The deliverable here is the live product, along with a plan to maintain it (see information on the maintenance phase below) and documentation around what's been delivered.
Monitor the live product for any bugs or issues that were missed in the quality assurance phase, and as the project manager, you'll need to be in constant communication with stakeholders or clients to make sure everything is unfolding according to expectations.
6. Maintenance
Next, the team will perform maintenance on the product according to the plan laid out in the previous step. Be clear with stakeholders or clients about what is included in the plan as regular maintenance and what is out of scope and may incur an extra cost (e.g. new features, additional pages, etc.).
3 Use Cases For Waterfall Project Management
Waterfall project management works best for projects that have well-defined deliverables and constraints as well as fixed budgets and timelines.
If your project scope still has a lot of unknowns or is subject to change, waterfall is probably not the project management approach you want to use. Waterfall works best for the following types of projects:
Construction Projects
Construction lends itself well to the waterfall method because a strict project management process helps ensure the safety of everyone working on the project or using the finished product.
This is because plans for buildings need to be signed off on by engineers and often government agencies before they can begin. Plans are not subject to change along the way, and a sequential plan can easily be followed.
Construction projects are sometimes referred to as capital projects. Read more about capital project management here and check out this list of the best construction project management software.
Website Design and Build Projects
Website design and build projects might use the waterfall process or one of many agile methods. Waterfall works well when needs are well-defined.
If you have an exact sitemap and style guide you need to use, it’s easy to plan out the phases and when each page will be ready for review and approval. You can also select your target launch date with a high level of confidence.
Software with Specific Functionality
If your team is building software with specific functionality and a well-defined set of requirements, the waterfall model might be the right choice. Examples of this might be a CRM system, HR software, or any type of compliance tool.
These will have an initial set of requirements, and the work can be scheduled and completed in a linear fashion. A Gantt chart showing the timeline and when stakeholders will receive status updates and/or need to be available for user acceptance testing will get everyone aligned with your plan.
Benefits of Waterfall Project Management
Here are the main benefits of using waterfall project management.
- Scoping and planning happen upfront: When scoping and planning happen upfront, there is less room for ambiguity or changes as the project progresses. Team members should have a clear understanding of who is going to do what and when they will do it.
- A clear plan and objectives: The project team and stakeholders have a shared understanding of the plan. If new ideas come up during the project, they can either be held for a new project or another phase of the work, or the project manager can initiate a change order. This keeps the project running smoothly and helps make sure it meets project objectives.
Drawbacks of Waterfall Project Management
These are the main drawbacks of the waterfall project methodology.
- Rigid structure makes change complicated: It can be challenging to make changes to waterfall projects. As technology advances quickly or user needs change, the project is not going to be as flexible as it would be if you were using one of the agile methodologies (e.g. Scrum or Kanban) or another methodology that allows for scoping work iteratively.
- The work may take longer to get done: Since the waterfall approach means initiation and planning is done upfront, it may take longer to get to a completed project or usable product. Agile teams release usable work more frequently, but in waterfall project management, the team waits until everything is ready to release work.
Agile vs Waterfall Project Management
The main difference between agile and waterfall is that agile focuses on iteration and adaptability and you can change your plan to accommodate new requirements and feedback along the way, but waterfall project management follows a linear plan from project start to finish.
In agile project management, work is spelled out in a backlog and completed in time boxed sprints. The sprints produce a workable product called an increment, and customer feedback is provided each sprint, usually in a demo.
What's Next?
Want to debate the relative merits of waterfall and various agile approaches? Join DPM Membership and get access to the conversation in Slack with 100s of other digital project managers! You'll also get access to 100+ templates for important project documents like project plans, risk registers, and statements of work.
