A Complete Guide to the Waterfall Project Management Methodology

“Management is, above all, a practice where art, science, and craft meet.” – Henry Mintzberg

If we were to explain the difference between the agile and waterfall methodologies to a child, we’d talk about puzzles and riddles.

Confused? Keep reading.

Puzzles, like the waterfall model, maybe complicated in nature but are predictable. You can solve it by placing the pieces one after another using set rules and stellar organizational skills. All in all, there’s a transparent system in place.

On the other hand, riddles – like the agile methodology – are more complex in nature and somewhat unpredictable. They require you to think on your feet, be alert, iterate often, and follow unconventional rules to get to the answer.

“Different people might have different (albeit incorrect) answers to the same riddle (think: agile), but with the case of puzzles (think: waterfall), the answer is consistent and linear.

In simplistic terms, the waterfall project methodology is one of the oldest, traditional project planning processes. Having first been described by Winston W Royce in the early 1970s, this methodology follows a sequential, linear process. In the early years of adoption, this methodology found solid footing in the construction and manufacturing industries out of necessity.

Phases of the Waterfall Project Management Methodology

The waterfall method comprises of six phases that follow a predictable timeline. The phases comprise of specialized tasks that are carried out by grouping project activities into sequential slabs. These ultimately look like slopes of a waterfall, flowing down a series of cascading rocks (thus the name ‘waterfall’):

Note that each phase depends on the deliverables of the previous phase, without which you cannot move down to the next phase. Additionally, every phase needs to be completed, reviewed, and approved before you can jump into the next step. To that end, here’s a high-level overview of what each phase entails:
Phase 1: Requirements Gathering

Since you cannot go back a phase with the waterfall methodology, accurate planning becomes  necessary. Here are the tasks you need to complete in this phase:

  • Conceptualize the idea and conduct a baseline assessment of the project, which includes the cost-benefit analysis.
  • Conduct a feasibility test.
  • Chalk out a clear and upfront requirements document based on your project’s demands and business needs. It should also include key elements such as the project’s objectives, scope, purpose, deliverables, and roles, as well as the responsibilities of each team member.
  • Collect information with regards to the project objectives and scope by conducting interviews, questionnaires, and interactive brainstorming.
  • Distribute the document among the team members to ensure everyone is on the same page (both literally and figuratively).

Phase 2: Design & Architecture

Think of this stage as integral to successful project planning. In the design phase, the following tasks are undertaken:

  • The design team creates diagrams related to software architecture, studies design requirements, and evaluates specifications to grasp what the end-product might look like. It also details the list of actions required to get there, in addition to choosing the right kind of technology.
  • The team then designs the required systems (based on the list created).
  • Coding does not occur at this stage. Instead, the team works on specifications such as programming language or hardware requirements.

Phase 3: Development

This is the “action-oriented” phase where the software engineering team/programmers:

  • Engage in coding using data from the previous stage to create a functional product.
  • Integrate smaller code stacks at the end of the phase or at the very beginning of the fourth phase.

Phase 4: Quality Assurance & Testing

One of the most critical phases in the waterfall development process, this phase involves the following steps, which can make or break your end-product:

  • Quality testing of the product is carried out by testers in addition to fixing bugs. They can also conduct a user acceptance test to understand how user-friendly the product is.
  • In case there are any serious issues, the project may require you to go back to the drawing board, or in this case, to phase one for re-evaluation.

Phase 5: Implementation/Delivery

Once the testing is complete, and no errors are found, the development team works towards executing deliverables as seamlessly as possible. The product/service is launched into the market, and all the planning is put into action.
Phase 6: Maintenance & Support

This phase revolves more around customer involvement and can be thought of as the final leg in the development process. The following tasks ensue in this phase:

  • In case of any issues arising from the client’s end, the team creates patches and updates to address them as promptly and as effectively as possible.
  • The team supports the customers, addresses their evolving needs, and maintains the system.

Here’s an example that details the different phases of waterfall methodology in software engineering:

  • Requirement Gathering: In this stage, an in-depth list of requirements of the software system to be developed is gathered from the client.
  • Design: This stage includes planning the technical details of the project, such as the programming language (Java, PHP, .net) and database such as Oracle, MySQL, etc.
  • Built: Here, the coding team initiates the coding of the software.
  • Test: The software is tested to ensure that it meets the client’s specifications.
  • Deployment: The application is deployed in the respective environment.
  • Maintenance: This stage involves addressing any client’s requests and making changes to the code as per the changing requirements.


Advantages of the Waterfall Method

“Though less common these days, when your end product’s requirements are fixed, yet time and money are variable, choose the waterfall method. I like to imagine a scientist doing research for a big company—through trial and error, he’ll likely restart his whole process many times and at different stages to get the coveted final result. Through waterfall project management, this behavior is anticipated and even preferred! This enables members to adjust and re-think their approach time and time again.” – Patrick Rockwell

Some key benefits of this software development process include:

  • Follows a set pattern and a rigid process, making the processes simpler to implement and manage.
  • Requires specific components in every phase, that need to be achieved and reviewed, giving you greater control.
  • Offers a functional flow and ensures thorough documentation early on in the project development process.
  • Fosters a culture of discipline, helps to share progress easily, ensures seamless reporting on missed deadlines, and eliminates risks without creating complications.
  • Allows for simple training, making it easy for first-timers to understand.
  • Establishes key milestones and concrete goals, thereby allowing managers to track progress from start-to-finish.
  • Takes the guesswork out of where the progress stands in terms of performance, development, etc.
  • Allows for better resource planning among team members as the scope of work is set in advance.
  • Its in-depth documentation and thorough conceptualization allow for saved time and money from both the developer as well as the client’s end.
  • Gives way to better application design as the requirements and deliverables are documented in great detail.


Disadvantages of the Waterfall Model

Here are the top disadvantages of using the waterfall method:

  • It does not accommodate iterations or changes across the stages of the software development life cycle.
  • It may be challenging for clients to define their scope of requirements in an exact manner in the early stages of a project.
  • It involves considerable risk-taking and uncertainties.
  • It does not work well for longer duration projects that require constant revisions.
  • Mid-process user/client feedback relating to fundamental flaws cannot be worked upon unless the team goes back to the basics. This makes it a costly and time-consuming affair.
  • A delayed testing period can make “testing” look like an afterthought instead of addressing issues at the very beginning.


Wrapping Up: The Waterfall Effect

“A known project, that is repeatable and requires rule-following might be managed under the Waterfall model.” – Dave Snowden’s Theory of Complexity (Cynefin framework)

In a nutshell, the waterfall methodology is rooted in logic and sequence. By extension, it works wonders for short projects that are well-defined from the start and need a tight structure. Comprising of distinct stages, this methodology can be used if the project requires little changes and deadlines need to be set and maintained. In rare cases, a hybrid management method called “Agifall” is used, which combines the best aspects of the waterfall and agile project management methods.