The Waterfall Model: Advantages and Disadvantages

5 min readFeb 2, 2021
Photo by Startaê Team

While time is linear, not much else involved in project management is. As projects continue to increase in complexity, it can turn a project manager’s job into a nightmare. A team may take two steps forward, and then a setback occurs that forces them to move five steps back.

A linear model that can work for some teams is the waterfall model, which uses a sequence of steps that moves onto the next step after completing the previous one. While this model works for smaller projects with a clear objective, it might not work for projects entailing more complex tasks.

The information below explains the waterfall model and why it might not be the best option for your team. Later, a suitable alternative for many projects will be introduced called the agile model.

What Is Waterfall Model?

Waterfall model is a project management approach that requires taking a logical progression of steps to reach project delivery. Also known as linear-sequential model, waterfall relies on teams following a sequence of steps and never moving forward until the previous step has been completed, meaning no steps overlap.

When to Use Waterfall Model?

The waterfall model is most commonly used in software engineering and product development, less often — in other projects and industries.

Employ the waterfall model only if your project meets the following criteria:

  • All the requirements are known, clear, and fixed
  • There are no ambiguous requirements
  • The project is short and simple
  • The development environment is stable
  • Resources are adequately trained and available
  • The necessary tools and techniques used are stable, and not dynamic

If your project doesn’t fit this description, consider one of the following most common waterfall model alternatives:

The Six Phases of the Waterfall Model

The waterfall model has the following six stages:

  • Requirement Analysis: The model’s initial stage involves defining all the project’s function and nonfunctional requirements. Functional requirements pertain to the project’s external fulfillments, such as obtaining credit-card validation for activating a free trial. On the other hand, nonfunctional requirements involve technicalities, such as measuring performance.
  • System Design: After the requirements have been analyzed, they can be transformed into a design or flow chart. The project specifications are created and studied to determine what the final project will look like, along with the required actions to get there.
  • Implementation: In software development, this stage is where the actual coding begins. All the work compiled in the previous steps is applied to this stage to start implementing the project findings.
  • Integration and Testing: After the coding is completed, testing rounds begin. The product is not prepared to be delivered to the customer until all bugs have been sorted out. An optional user acceptance test (UAT) might be performed at this stage, which involves a small group of initial users testing the product.
  • Deployment: The deployment stage involves the release of the software. The product is complete, and the development team releases the deliverables.
  • Maintenance: After the product has been released to the public, new issues may be brought to the developer’s attention. The development team remains responsible for providing solutions to the problems and updating the software based on the feedback.

All these stages flow downwards one-by-one like a waterfall. The next stage is started only after the previous one is over.

Advantages and Disadvantages of Waterfall Model

If you’re considering using the waterfall method for your next project, here are the five main advantages and disadvantages of the waterfall model that your team will most likely experience:

Advantages of Waterfall Model

  • Before the next project phase starts, each previous phase must be completed, meaning early roadblocks elimination and more polished products in the end
  • Determines the end goal early, meaning strong commitment to the end result
  • Before each stage is completed, quality assurance tests must be taken, meaning fewer chances of issues and roadblocks
  • Elaborate documentation is compiled at every stage to ensure quality results
  • Project is completely dependent on the project team with minimum client intervention, meaning teams work their way through to the project goal without frequent fixes and adjustments from the client’s side

Disadvantages of Waterfall Model

  • You can’t apply this model to complex projects with changing requirements due to the rigid sequential approach
  • This approach excludes the client from the development process, meaning high chances of late change requests and unmet deadlines
  • The testing period comes late in the development process and doesn’t allow simultaneous development and testing to fix issues at the early stages
  • Documentation writing takes a lot of time
  • You can’t use feedback from your clients to adjust the product to their needs, meaning lower customer satisfaction

Waterfall Model Vs. Agile

Arguably the more common model of the two, the agile process describes an alternative method that relies on the product, its people, and communications. Agile development is much more flexible in nature compared to the waterfall model. It combines a variety of tools to create a more efficient software development process.

At its core, the work completed in an agile process still closely resembles the waterfall model. The model still requires designs, requirements, development, and the integration of other products. Finally, the product is tested and modified according to the testing results until it is ready to use. The main difference between the two models is that the agile model uses an empirical control method, which means there is more focus on evaluating and continuing based on the current observations. Rather than moving through clear-cut stages, the agile process adapts depending on the actual project’s status.

Whether your team decides to opt for the waterfall model or the agile model, they could benefit from using project management software. actiTIME is an intuitive app for managers to plan their waterfall- or agile-based projects. It allows them to create tasks, assign them accordingly, and keep a close look at task progress. actiTIME can help you detect any problems hindering team performance in a waterfall or agile-based project.




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