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What is Waterfall Methodology: Advantages & Disadvantages

20 May 2022
What is Waterfall Methodology: Advantages & Disadvantages

The Waterfall methodology is one of the most popular, oldest and most traditional methodologies in project management. This type of methodology is followed in a project where requirements are well-known and fixed and no further changes are expected.

waterfall methodology

What is the Waterfall Methodology?

The waterfall methodology is a linear sequential design process, originating in software development processes. The Waterfall model was developed by Winston Royce and presented in 1970. The waterfall development method originates in the manufacturing and construction industries. It gives highly regimented physical environments that are very difficult or impossible to change or adapt once work has begun.

In the early days of software development, there was no concept of Agile methodology or iterative life cycle.

In fact, until the late 1990s, the majority of software projects followed a simple “waterfall” life cycle. Requirements were gathered upfront; the solution was designed, built, and tested. The release to users for acceptance testing (UAT) occurred, followed by bug fixes before the final production release.

This Waterfall approach worked well for many IT projects because they tended to be tightly scoped in both time & cost. It works with relatively fixed requirements that did not change much during the course of the project. Projects were small enough for management of changes, often by adding an extra week or two to the project timeline. This adjustment rarely caused significant problems.

6 Common Stages in a Waterfall Project Management

The Waterfall Methodology is not exactly a method as much as it is an approach, however, the six distinct stages that make up this cycle are very common in most software development processes.

stages of waterfall methodology

Phases of Waterfall Methodology

The number of stages involved can vary depending on the project but these six stages are the most common among all projects using the Waterfall model. Following is an overview of each stage of the Waterfall project management process and what each one entails:

1)   Requirements - The Discovery Phase

The first phase of the Waterfall model is to gather all the requirements for the project, which are usually outlined by the client. The team will conduct interviews, research and review existing documentation to determine what needs to be done. This phase is often called "the discovery phase."

To understand what a business organisation needs, you must first listen to its stakeholders and collect as much information as possible. Make sure you are not rushing into planning or design without a clear understanding of your client's business goals, target users, and any potential obstacles that may arise later in the process.

2)   Design

In the second phase, the project begins with a design process that outlines the end result and how it will be achieved. This is typically a very detailed plan and is highly unlikely to change throughout the project since there are no opportunities for re-work later on in the process. Once this step is complete, it moves to implementation.

3)   System Testing

In this next phase, all system components are tested. This includes an integration test, which makes sure that each part works properly with the others; a functional test, which guarantees that all functionality meets requirements; and a test of performance, which ensures that the system can handle peak loads without crashing or slowing down significantly.

4)   Implementation

During the implementation phase, each element of design is put into place one at a time, with each team member completing their assigned tasks in sequence before passing on their work to the next individual or group in line. There is not a lot of overlap or communication between teams during these phases—each team stays focused on their own piece of the puzzle until they finish and pass it on (hence the waterfall name).

5)   Verification/Integration

Once every element has been completed according to plan, these pieces are put together through integration and verification testing processes that ensure all elements fit together seamlessly as intended at each phase of development by validating that each feature works properly and meets its requirements before moving forward to create more features — even if those additional features do not work properly yet when combined with others that have already been developed because they are not ready to be tested yet as part of integration verification.

6)   Maintenance

After the project is completed, any bugs that are found are squashed, and customers get to actually use the finished product. Maintenance also applies to adding new features or functionality. This phase may come after the product has been completed and used by customers, and it could potentially end as soon as you are happy with the finished product.

Advantages and Disadvantages of the Waterfall Methodology

Although the Waterfall methodology is one of the most stringent and planned out project management approaches, it is not without its set of advantages and disadvantages.

 advantages and disadvantages of waterfall methodology


Presence of a Clear Structure.

The waterfall methodology follows a distinct structure. It is a sequential model which consists of different phases, each phase having its own set of goals and deliverables. The initial phase consists of the analysis of the project requirements. This is followed by the designing, testing, implementation, verification and the maintenance phase. The requirements are determined in the early stages and remain constant throughout the development life cycle. The final result is delivered in the last phase i.e., the maintenance phase.

Smooth Transfer of Information

Each phase in the Waterfall project management approach has a specific deliverable. Information about the project easily passes from one phase to another. This ensures a smooth transfer of knowledge between team members. As this knowledge is often presented through documentation, this allows other teams (e.g., maintenance or support) to easily pick up where previous ones left off should the need arise.

Easy to Manage

As mentioned above, the Waterfall methodology has a clear structure with well-defined goals and deliverables for each phase of the project life cycle. Thus it is easy to manage this type of project as every milestone has to be achieved before going to the next level. Due to this, it becomes easier to track the progress of work. It is easy to identify any kind of bottlenecks or delays that might have occurred during any phase.

Early Determination of Goals

The Waterfall model's initial phase involves extensive planning, research, and brainstorming. It helps determine goals and objectives before actual work begins. This planning ensures your team has a clear idea of what they aim to achieve and how they will approach it.

Extremely Stable

The Waterfall methodology follows a linear approach which means it is extremely stable in nature. There are no chances of deviation from the original plan once the system requirements have been finalised. This makes it easier for managers to predict any potential problems during execution.


Costly and Inflexible

The Waterfall model is a linear sequential design process, meaning that you have to complete one phase before moving on to the next phase. This process is highly structured and regimented in a way that does not allow for much flexibility.

All phases of the project need to be completed before you can move on to testing. As a result, if your client decides to add or modify something late in the process, it may require going back through all previous phases — which could be costly.

Does not Prioritise the Client or End-User

Unlike other software development models, the Waterfall project management approach does not prioritise feedback from customers when developing a product. Instead, it focuses on meeting requirements that were determined earlier in the project lifecycle. The problem with this approach is that requirements can change — especially as users start using your product and providing valuable feedback.

Delayed Testing

The Waterfall methodology does not allow for testing until it reaches the final stage of the development process, which is known as system testing. However, it can create an issue because by then, many resources would have been applied to each preceding stage. So if testers find any issues at this stage, business owners can incur losses caused by rework.

No Scope for Revision or Reflection

When you are working on a project that is made up of many parts, it is important to be able to make revisions and reflect on what has been accomplished so far. This approach always may not work, since you are not able to go back and make revisions. To do this, you get to the end of each phase and then make revisions. Especially if you need to shift in a different direction than planned before the completion of each stage.

Waterfall vs Agile Methodology: What's the Difference?

If you have a big, sprawling project that involves lots of moving parts and stakeholders, you are probably working on a waterfall methodology. The idea is to have a plan and then move forward at the same time.

waterfall methodology vs agile

If your team members are used to working in an iterative, agile environment, they are going to have trouble adjusting to a more top-down approach. But that does not mean they cannot work together effectively. In fact, the most successful agile teams are those that work together well and effectively throughout the entire process.

Agile Project Management is about rapid testing, frequent delivery, and continuous refinement. That is great for projects that require constant updates, like selling software or taking down a website when something goes wrong. However, it is not so good for projects that need to be built from scratch.

waterfall methodology Certification

For this reason, agile methodology is focused on short-term projects that deliver value quickly, while long-term projects remain stuck in the planning and implementation phase. Agile development emphasizes collaboration and communication throughout the project lifecycle. It involves iterative planning, and changing plans during implementation. This ensures all parties work toward a common goal.

If you are interested in learning more about Agile, the Institute of Project Management offers a Certified Agile Project Management course. This course is focused on explaining different Agile modules. That way it broadens your knowledge of Agile project management. Which upon completion of the course, is testified by IPMA Agile certification.

Waterfall Project Management

Waterfall Project Management is focused on long-term projects and tends to rely on a more approach of hierarchy, documentation and bureaucracy. This process is more commonly used for software development, but it can be applied to any product development process.

In addition, it involves putting everything into place before any code is written. If you're building a website, for example, you'll want to decide on the look and feel of your site before you start coding anything at all. Then you'll create wireframes and mockups as an early step in creating the actual site. From there, you can build the pieces of your site one by one until it's done.

What is the Waterfall Methodology Used For?

The waterfall Model has proven to be an effective approach for a variety of endeavours, including:

  • Software development. Software projects can be complex and take years to complete. The Waterfall methodology breaks each project into manageable tasks, allowing the development team to focus on one aspect at a time before moving on to the next.
  • Systems engineering. When engineers create systems that include multiple components, they must ensure that all parts fit together seamlessly from start to finish. Each component is worked on individually using the Waterfall model, ensuring every element fulfils its purpose when integrated with others.
  • Project management. "From construction projects to marketing campaigns, the Waterfall process aids project management teams in coordinating tasks effectively. This ensures each phase is completed in a timely manner. Subsequently, the team can smoothly progress to the next step.
  • Manufacturing. Applying an assembly line method to create each product part essentially follows the Waterfall project management approach in manufacturing.
  • Process engineering. Due to their strict sequencing of activities, many factory production processes require engineers to use this model. It is suitable when designing them from scratch or making changes according to new regulations or quality requirements.