What is the Waterfall methodology?

The Waterfall methodology is a project management approach that emphasizes a linear progression from the beginning to the end of a project. This methodology, often used by engineers, is front-loaded to rely on careful planning, detailed documentation, and consecutive execution.

The Waterfall methodology — also known as the Waterfall model — is a sequential development process that flows like a waterfall through all phases of a project (for example, analysis, design, development, and testing), with each phase completely wrapping up before the next phase begins.

It is said that the Waterfall methodology follows the adage to “measure twice, cut once.” The success of the Waterfall method depends on the amount and quality of the work done on the front end, documenting everything in advance, including the user interface, user stories, and all the features’ variations and outcomes.

With most of the research done upfront, estimates of the time needed for each requirement are more accurate, which can provide a more predictable release date. With a Waterfall project, if parameters change along the way, it’s harder to change course than with Agile methodology.

The key benefits of the Waterfall methodology include establishing clear and consistent requirements at the start of each project and making it easy to set timeframes and measure progress. The key benefits of the Agile methodology include increased ability to be flexible and adapt to change at any stage in the project, and better communication as face-to-face is prioritized.

In this guide:

• What is Waterfall software?
• Waterfall methodology phases.
• Waterfall process vs. Agile methodology.
• When to use Waterfall methodology.
• Benefits of Waterfall project management.
• Disadvantages of Waterfall project management.
• How Waterfall methodology varies by industry.
• Best practices for Waterfall project management.

Waterfall software helps project managers manage projects using the Waterfall method. As Waterfalls are a relatively complex, phased approach, they require close attention and coordination.

Waterfall software can be desktop or cloud based. It helps you:

• Structure your processes
• Organize tasks
• Set up Gantt charts and schedules
• Monitor project progress
• Visualize project phases, dependencies, and subtasks
• Provide workers and stakeholders with accurate timelines and deadlines for each project phase

Waterfall software is used across various situations, projects, and industries. These include:

• Projects where the requirements are already well-defined and minimal changes are expected
• Larger-scale projects with lengthier timelines
• Projects where a high level of confidence is needed from stakeholders regarding the outcome
• Industries such as construction, aerospace, and manufacturing

The Waterfall methodology follows a chronological process and works based on fixed dates, requirements, and outcomes. Individual execution teams aren’t required to be in constant communication and are usually self-contained, unless specific integrations are needed.

Team members also tend to work independently and aren’t expected to provide status reports as often as with the Agile approach. Usually, one phase doesn’t begin until the previous one is finished.

Using a software development project as an example, the Waterfall process usually includes stages that look like this:

Requirements.

The Waterfall methodology depends on the belief that all project requirements can be gathered and understood upfront. The project manager does their best to get a detailed understanding of the project sponsor’s requirements. Written requirements, usually contained in a single document, are used to describe each stage of the project, including the costs, assumptions, risks, dependencies, success metrics, and timelines for completion. Once all the project requirements have been defined, the team is left with a clear outline of the entire project lifecycle.

Design.

Here, software developers design a technical solution to the problems set out by the product requirements, including scenarios, layouts, and data models. First, a higher-level or logical design is created that describes the purpose and scope of the project, the general traffic flow of each component, and the integration points. Once this is complete, it is transformed into a physical design using specific hardware and software technologies.

There are two phases of system design: high-level and low-level. The high-level design phase is where the team creates a skeleton of how information will be accessed and how things will work. Then at the low-level phase, each specific part of the software is defined and fleshed out.

Implementation.

Once the design is complete, the next stage of the Waterfall method is technical implementation. This might be the shortest phase of the Waterfall process because painstaking research and design have already been done. In this phase, programmers code applications based on project requirements and specifications, with some testing and implementation also taking place. If significant changes are required during this stage, this may mean returning to the design phase.

Verification or testing.

Before a product can be released to customers, it needs to be tested. This helps confirm the product has no errors and all the requirements have been completed, ensuring a good user experience with the software. The testing team will check the project management methodologies and turn to the design documents, personas, and use case scenarios supplied by the product manager to create their test cases.

Deployment and maintenance.

The deployment phase is when the software, product, or final deliverable is released to the end user — the customer. A smooth rollout requires coordination and careful planning. Once the software has been deployed in the market or released to customers, the maintenance phase begins. As defects are found and change requests come in from users, a team will be assigned to take care of updates and release new software versions.

While the Waterfall model relies on thorough up-front planning in which each phase must be fully completed before the next one starts, Agile is a more flexible, iterative process that tackles the planning, design, implementation, and testing tasks in shorter, repeating cycles.

The key differences between the Waterfall process and Agile methodology are:

• The approach to the project. Waterfall has a linear approach, while Agile has a more adaptive approach.
• Flexibility. Waterfall processes have very limited flexibility, whereas Agile methods can be more easily changed.
• Customer involvement. Customers have very limited involvement in Waterfall processes.

The Waterfall process is adopted by project managers who are faced with development projects that:

• Have a clearly defined goal
• Have no or minimal restrictions on budgets and timescales
• Work for clients with a clear idea of expected outcomes
• Create repeatable processes

If a project manager prefers clearly defined processes, where cost, design, and time requirements are known upfront, then the Waterfall method is the way to go, as long as the project itself is conducive to those constraints.

The Waterfall methodology is a straightforward, well-defined project management methodology with a linear approach and a proven track record. Since the requirements are clearly laid out from the beginning, each contributor knows what must be done when, so they can effectively plan their time for the project’s duration using a sequential approach.

Other benefits of the Waterfall process include:

• Developers can catch design errors during the analysis and design stages, helping them to avoid writing faulty code during the implementation phase.
• Project managers can accurately estimate the total cost of the project as well as the timeline, once the requirements have been defined.
• Project managers can more easily measure progress according to clearly defined milestones because of the structured approach.
• Developers who join the project in progress can easily get up to speed because everything they need to know should be in the requirements document.
• Customers aren’t constantly adding new requirements to the project, delaying production.

Like any development process, the strengths in one area might mean weaknesses in the other. The Waterfall methodology’s insistence on upfront project planning and sequential approach with a commitment to a certain defined progress means that it is less flexible, or agile, later in the game. Changes that come further in the process due to late-stage testing can be time-consuming, painful, and costly. Customer involvement is limited with the Waterfall process.

Other reasons the Waterfall methodology may not work include:

• Projects can take longer to deliver with this chronological approach than with an iterative one, such as the Agile method.
• Clients often don’t fully know what they want at the front end, opening the door to requests for changes and new features later in the process when they’re harder to accommodate.
• Clients are not involved in the design and implementation stages.
• Deadline creep — when one phase in the process is delayed, all the other phases are delayed.

Waterfall methodology can vary depending on the type of sector or industry it is used in.

Waterfall in software development.

Waterfall processes used in software development form the basis of most life cycle models within this industry. Most other types of software development methodologies are a derivative of Waterfall. The rigorous planning and clear project structure of this methodology are ideally suited to software development.

Waterfall for B2C.

Waterfall methodology for B2C is not always the most effective tool. When marketing products directly to the end user, more customer input may be required than can be implemented using Waterfall processes. However, B2C companies focusing on large-scale projects can successfully implement the Waterfall process. Examples include Microsoft and IBM, which both use Waterfall to develop products that are then marketed directly to the consumer.

Waterfall for B2B.

Waterfall methodology for B2B allows companies to create a powerful framework for the management and optimization of the process of lead generation. The Waterfall process can help to enhance lead management, improve alignment between different teams, such as marketing and sales, and drive continued revenue growth.

• Clear communication and collaboration: Consistent and transparent communication ensures that all stakeholders understand project goals, timelines, and expectations. Collaboration between teams helps avoid misunderstandings and keeps the project moving forward smoothly.
• Detailed documentation: Comprehensive documentation at every project stage helps maintain clarity and provides a reliable reference for requirements, timelines, and responsibilities. It also ensures continuity if team members change or if the project is revisited in the future.
• Effective risk management: Identifying potential risks early allows teams to create mitigation strategies before problems arise. This proactive approach reduces delays and helps keep the project within scope and budget.
• Use of project management tools (such as Gantt charts, Work Breakdown Structures, Critical Path Method): Tools like Gantt charts, work breakdown structures (WBS), and the critical path method (CPM) help visualize timelines, task dependencies, and key deliverables. These tools support better planning, monitoring, and control throughout the project lifecycle.