What is the waterfall methodology in software development?

What is the waterfall methodology in software development?

The waterfall methodology is one of the software development methodologies used by many developers for project management. It takes a linear approach from project start to finish, which means that each phase of the development process must be completed before moving on to the next. Many organisations have achieved the desired results by utilising this approach, which is structured and thorough and has been used for several years.

Waterfall methodology begins by gathering customer and stakeholder requests at the beginning of the software project so that a sequential project plan can be developed. So, all the aspects of the project will be documented beforehand, including user stories, interfaces, features, etc., allowing you to generate accurate time estimates and establish a predictable release date. You will discover more about the waterfall methodology, its stages, benefits, and drawbacks in this article.

Five standard phases in the waterfall methodology

As mentioned earlier, the methodology works chronologically, relying on fixed requirements, dates, and outcomes. Therefore, it does not require teams to collaborate unless specific integrations are constantly needed. They usually work independently, unlike in Agile methods, which require the team members to provide frequent status reports and collaborate. 

This section will cover the five main phases or steps of the waterfall method as originally proposed by its creator, Winston W. Royce. Furthermore, every stage of software development starts only after the last one is finished. When considering a software development project, the following steps are typically included in the process:

  • Requirements
  • Design
  • Implementation
  • Verification or Testing
  • Deployment or Maintenance

1. Requirements

The first phase is all about collecting and fully understanding the project requirements of the customer and stakeholders. The project manager will do the task, which will allow the team to plan the subsequent phases accordingly. Typically, all of the requirements are recorded in writing as a single document to ensure accuracy. 

It will outline the expenses, presumptions, risks, dependencies, success metrics, and completion dates for every phase of the project. Theoretically, communication with customers will not pick back up until the product is completed after the first phase is finished. 

2. Design

During the design phase, software developers solve technical problems posed by the requirements of the product. The solution can be layouts, scenarios, data models, etc. The first thing they do is draft a design that outlines the goal and parameters of the project, as well as the general path of each component’s traffic and integration points. It is called the logical design subphase.

Then, the draft design is transformed into a physical design using specific hardware and software technologies in the physical design subphase. In this phase, all the ideas discussed in the logical design subphase get converted into actual specifications via the team’s hardware and software technologies of choice.

3. Implementation

Now comes the implementation phase, the stage where everything is put into action. It is usually the shortest waterfall phase because all of the research and design should be finished at this point. In this phase, the programmers will make use of the specifications and requirements from the design phase to develop code. The team might have to go back to the design phase, though, if any significant adjustments are needed during the implementation phase.

4. Verification or Testing

Verifying or testing a product before it is released to customers is a significant waterfall phase that cannot be avoided, no matter what. It is necessary to guarantee that the product is error-free and that all requirements have been met in order to provide a positive software user experience. So, in this stage, the development team will hand over the project to the QA testing team.

  • Before the project is deployed, they will look for any bugs or errors that need to be fixed, and they will thoroughly record every problem they discover during quality assurance. 
  • If another developer encounters a similar bug, they can use the prior documentation to assist in resolving the problem. 
  • Following error testing, the finished product is then made available to the customer during the verification phase. 
  • The customer will inspect the finished product to make sure it meets the requirements that were specified at the start of the project.

5. Deployment and Maintenance

After verification and testing, the product is deployed to the customer by the correct deadline. But there are instances where a new bug is discovered or a software update is required once the product is deployed. So, in the maintenance phase, the team can make the necessary fixes and release updated software versions to ensure complete customer satisfaction. It is common in software development to continuously work on this phase.

How does it benefit you?

Given what you have read in the previous sections, waterfall methodology is a clear-cut, straightforward approach to project management that has been adopted by numerous organisations over the years. Since you will be aware of the project requirements from the start, the team will know what and when it must be done and will be able to plan the project well in order to complete it by the given deadline. The following are a few benefits of the method:

  • By identifying design flaws early on in the requirements and design process, developers can help prevent writing bad code later on in the implementation phase.
  • Once the requirements are established, it is possible to estimate the project’s total cost and timeline with accuracy.
  • Measuring progress in accordance with well-defined milestones is made simpler with an organised approach.
  • When new developers join an ongoing project, they will have no trouble getting up to speed because the requirements document should contain all the information they require.
  • Customers bringing on new requirements for the project will not cause a delay in production.

What are the drawbacks?

The advantages in one area could lead to disadvantages in another, just like in any development process. Due to its emphasis on upfront project planning and dedication to specific, defined progress, the waterfall methodology is less adaptable later in the process. Making changes later in the process can be painful, time-consuming, and expensive. There are additional reasons why the methodology might not be effective.

  • Compared to an iterative approach like the Agile method, a project may take longer to complete when using this chronological method.
  • Due to their inability to express their needs clearly upfront, clients may request modifications and new features later on in the process, when it will be more challenging to fulfil them.
  • The stages of design and implementation are not open to client participation.
  • A process known as “deadline creep” occurs when one step is postponed, and so are all the others.
  • The approach’s main drawback is that once a phase is finished, it can be challenging to go back to.

So, you learned a lot about the waterfall methodology in this article. This approach may not appeal to every software development project. The method is typically preferred by project managers who manage projects with precise requirements that provide a clear picture of how things will unfold from the beginning and are unlikely to change scope after the project begins. For some projects, the approach might seem unduly restrictive, but it can be an excellent tool to prevent a clearly defined, predictable project from going over budget and schedule constraints. So, make an informed decision based on the information in the article.

Interesting Links:

Check out more information about the Waterfall Model in Software Development

What are the advantages and disadvantages of Waterfall Methodology?

Pictures: Canva

The author: Sascha Thattil works at Software-Developer-India.com which is a part of the YUHIRO Group. YUHIRO is a German-Indian enterprise which provides programmers to IT companies, agencies and IT departments.

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