GUIDE 2024

What is the Waterfall Model?

Interested in learning about the most traditional and foundational software development processes?

The waterfall methodology is a linear project management approach that has been used for about 50 years now. In the waterfall model, stakeholder and customer product requirements are collected at the beginning of the project, and then sequential phases are created to accommodate those requirements.

Let’s take a better look at what the waterfall method is:

What is the Waterfall Model? 

The waterfall model emphasizes that projects should follow a logical progression of steps throughout the software development life cycle (SDLC).

As the name implies, each phase of the project cascades into the next, progressively following down like a waterfall. If you’re interested in learning more via video, then watch below. Otherwise, skip ahead.

The sequence followed by the Waterfall approach usually follow:

1. Gather the Requirements

During this first phase, the potential requirements of the product are methodically collected and written down in a specification document. With this requirements document, project managers plan out every other phase without further customer correspondence until the product is complete. It is assumed that all the requirement gathering happens at this phase.

2. Analyze Requirements

With a compiled of ideas that define what the application should do, the next step is to transform them into an actionable plan. During this second stage, you should properly generate the models and business logic that will be used in the application. 

3. Translate Business Needs Into Tech Requirements

In this phase, design specifications need to be created to outline how exactly the business needs covered in the requirements document will be implemented — technically speaking. This design process covers technical design requirements, such as programming language, data layers, services, etc. 

4. Development

This is the implementation phase, when the actual source code is finally written, implementing all models, business requirements, and integrations that were specified in the prior stages.

5. Test the Application

In this testing phase, QA and beta testers systematically locate and report problems within the application. From this stage, the project often goes back to the previous stage (sometimes even goes back to the design phase), where the code is re-written, in order to ensure the bugs are fixed. In this case, the project needs to go through testing again, until it is cleared by testers.

6. Launch the Product

At this stage, the application is ready for deployment to a live environment, where users can access it and get back to you with more feedback. It is key that customers review the product to make sure that it meets the requirements laid out at the beginning of the project. After the product release, it’s important to maintain subsequent support on the product to keep it functional and up-to-date.

Waterfall Vs. Agile: Which One to Choose

The main difference between them is that waterfall projects are completed sequentially while agile projects are completed iteratively in a cycle.

When starting new projects, companies face the decision of choosing which development methodology to use. The most common doubt is between using an Agile approach or a Waterfall development methodology.

Both methods of development projects are widely used but have completely different approaches to product development lifecycle.

Waterfall projects can be broken down into several distinct phases. There is an ordered set of phases, and each phase needs to be completed one by one. Phase two cannot be started until the previous phase has been completed.

On the other hand, Agile projects are based on small phases that can happen simultaneously, involving various team members. These individual deliverable pieces are called sprints and last just a few weeks. Once each sprint is completed, the feedback is used to plan the next phase.

Both Kanban and Scrum, which you might have heard of, are two powerful instruments based on Agile.

Today, Agile is used more often. However, that shouldn’t serve as a base for you to determine the approach you’re going to use. Both processes have advantages and work better for different types of projects.

Waterfall Model Project Management Pros and Cons

The best way to understand if the waterfall methodology is the best for your project is by analyzing the advantages of using it as well as the drawbacks. Let’s explore:

Waterfall Pros

  • The waterfall method requires extremely meticulous documentation which means there will be good references for future products. In addition, if anyone suddenly leaves the development team, the strong documentation will allow someone else to pick it up quickly, which minimizes the impact on product deadlines.
  • Both the development team and customers spend time early in the life cycle agreeing on what will be delivered which allows everyone to have a better idea of what to expect in terms of size, cost, and the timeline for the product.
  • Since the design aspect is completed fairly early on, software engineering can work on multiple components in parallel
  • There is tangible output at the end of every single stage which means that all stakeholders can feel more comfortable seeing progress being made

Waterfall Cons

  • The process of gathering requirements from customers is a really tough process from the get-go because customers may not necessarily have a good sense of the final product even if you give them wireframes and mockups. Because of this, there is a good chance that the customer will be unhappy with the final product since they can’t see what is being delivered until it is almost finished
  • The waterfall plan doesn’t take into account users’ evolving needs so if the team discovers that the user demands different changes later in the process, it is very difficult to go back and from the beginning
  • Feedback and testing are deferred until very late in the development cycle so bugs can severely impact how another code was written if discovered late

Ready to Lead a Waterfall Model Project?

Ideally, your team should be using the waterfall methodology if there is a very clear picture of what the final product will be and if you know that your users won’t have changing needs once the project has begun.

It is also common to see organizations transitioning into more of a hybrid product development methodology that combines aspects of both Agile and Waterfall.

In our next post, we discuss the Agile methodology, which was developed to address many of the disadvantages of the waterfall method.

Interested in discussing the Waterfall methodology with other product managers? Meet and chat with product leaders around the world in our PMHQ Community!

Clement Kao
Clement Kao
Clement Kao is Co-Founder of Product Manager HQ. He was previously a Principal Product Manager at Blend, an enterprise technology company that is inventing a simpler and more transparent consumer lending experience while ensuring broader access for all types of borrowers.