Waterfall Model in SDLC
In this article, I am going to discuss Waterfall Model in SDLC. Please read our previous article where we discussed Test Maturity Model (TMM).
What is Waterfall Model?
A sequential software development process that adopts a methodical and linear approach is known as the waterfall paradigm. It comprises various phases, each of which builds on the outcomes of the preceding phase. The reason it is called “waterfall” is because the progress is downward-flowing and resembles a waterfall. The concept is broken down into several phases, and each phase has unique goals and requirements.
It serves as the first strategy and fundamental model in software development. It is a straightforward model that is simple to use and comprehend. The execution occurs in sequential order, so the output of one step equals the input of a subsequent stage. It is also referred to as the Linear-Sequential Life Cycle Model for this reason. Every step should be finished before going on to the next stage in order to prevent the overlap problems that come with several phases. According to the waterfall model, each stage’s deliverables—such as requirements—are moved to the design phase, the design is then moved to the development phase, and so on. We will frequently employ the waterfall paradigm when dealing with Life critical (hospital applications) and Machine critical (military projects).
What is the use of the Waterfall Model in SDLC?
The Waterfall model is a methodical, structured, and linear method of software development. It is frequently employed in projects where the requirements are clearly stated and are not anticipated to change considerably throughout the course of development. The main purpose of the Waterfall model is to give software development projects a well-organized structure. Here are a few of its primary goals:
- Timely Development: The Waterfall approach places an emphasis on a sequential flow of stages, with each phase having a unique set of deliverables and milestones. This methodical approach facilitates the development process of the organization and guarantees that each stage is finished before moving on to the next.
- Clearly Defined Project Planning: The approach calls for thorough planning at the project’s outset. Detailed requirements must be gathered and recorded, a project timeline must be made, and resources and expenses must be estimated. Prior planning aids in efficiently establishing timeframes, expectations, and resource allocation.
- Documentation: The Waterfall paradigm emphasizes documentation heavily. Each stage necessitates thorough documentation, which includes test plans, design documents, requirements specifications, and user manuals. Clarity is guaranteed, teamwork is made easier, and thorough documentation helps with system upkeep and improvement in the future.
- Risk Management: During the planning phase, the Waterfall approach enables early identification of potential risks and problems. Before making sizable investments, risks can be found and handled by carefully analyzing requirements and performing feasibility studies. This proactive approach to risk management aids in lowering project failure rates and unforeseen difficulties.
- Client Involvement: The Waterfall model gives clients the chance to participate and provide comments at particular points, usually during the requirements-gathering and testing phases. As the client’s feedback is taken into account during the development process, this ensures that the final product satisfies their expectations and requirements.
- Clearly Specified Milestones: Each step of the model has deliverables and milestones that are clearly specified. These checkpoints serve as milestones, enabling project managers to monitor development, assess the accomplishment of particular tasks, and confirm that the project is proceeding according to plan.
The Waterfall model has been used extensively in the past, but it has some drawbacks, including a lack of adaptability to changing requirements and a finite amount of area for repetition. As a result, different software development methodologies, including Agile, have become more and more common, particularly in projects with dynamic or growing needs.
Different Stages of the Waterfall Model in SDLC
Waterfall Model is a sequential model that divides software development into pre-defined phases. Each phase must be completed before the next phase can begin with no overlap between the phases. Each phase is designed for performing specific activities during the SDLC phase. It was introduced in 1970 by Winston Royce.
The waterfall model is a sequential approach to software development that is broken down into various phases that must all be completed before moving on to the next. The waterfall model is composed of the following phases:
Let’s quickly review each stage.
- Requirement Analysis and Gathering – The project requirements are gathered and outlined during this phase. This entails setting project goals, determining any constraints or limitations, and comprehending the needs and expectations of the client. For instance, if you were creating a website, you would learn about the target demographic, preferred design elements, and needed features.
- System Design – A system design is made using the requirements acquired in the preceding phase. Databases, software components, and the system architecture are all described. High-level diagrams, data flow diagrams, and user interface prototypes could be a part of the design. In the case of developing a website, you might produce a design blueprint outlining the site’s organization, navigation, and layout.
- System Testing – After the code is put into use, it is thoroughly tested. This step guarantees that the software satisfies the requirements, works as intended, and is bug- and error-free. Executing test cases allows for the identification and correction of any problems or flaws. The website would undergo testing to ensure that all links function properly, forms submit data reliably, and the website is compatible with various browsers.
- System Deployment – The program is either deployed to the production environment or made accessible to end users once it has been extensively tested and approved. This includes setting up the software on the intended system and making sure it functions properly. In the case of the hypothetical website, the created website would be put on a web server and made available to users.
- System Maintenance – The software then moves into the maintenance phase. At this stage, the software’s performance is monitored, faults and issues identified by users are fixed, and any necessary upgrades or enhancements are made. Regular content updates, correcting broken links, or adding new features based on user feedback are all examples of website maintenance.
What are the Advantages of the Waterfall Model in SDLC?
The waterfall model in SDLC is a well-known, systematic, and linear approach to software development. It has several disadvantages when compared to more contemporary methods, but it also has some benefits in certain situations. Following are a few benefits of the waterfall model:
- Simple and Well-Organized: The waterfall model has a sequential flow, which makes it simple to comprehend and use. The development process is clearly structured by the well-defined objectives, deliverables, and criteria for each phase before going on to the next.
- Documentation-Focused: The waterfall model places a strong emphasis on meticulous documentation at every stage. With this strategy, comprehensive documentation of all project requirements, design specifications, and test plans is guaranteed. For reference, maintenance, and knowledge transfer purposes in the future, thorough documentation can be helpful.
- Early Issue Detection: The waterfall model’s step-by-step progression enables early issue identification throughout the requirements, design, or implementation phases. Due to the ability to take corrective action early on, the likelihood of serious problems in the future is decreased.
- Simple to Manage: The waterfall model’s linear and sequential structure makes project management easier. Better scheduling, resource allocation, and planning are made possible by it. Well-defined project milestones and deliverables make it simpler to monitor progress and control expectations.
- Cost and Time Estimation: The waterfall model’s linear structure makes it simpler to predict project costs and completion dates. It is possible to estimate the resources and time needed for each phase when phases and deliverables are well specified, giving stakeholders a clear picture of the project’s scope and length.
What are the Disadvantages of the Waterfall Model in SDLC?
A sequential software development process that adheres to a rigorous and linear methodology is known as the waterfall model. Despite being widely utilized in the past, it has a number of drawbacks that have prompted the adoption of agile approaches, which are more adaptable and iterative. Some of the key drawbacks of the waterfall model are as follows:
- Lack of Flexibility: The waterfall paradigm is rigid and difficult to adapt to change. It is challenging to make modifications after a phase has been finished without affecting earlier phases. This may result in a strict and sluggish development process, especially if project requirements alter or fresh ideas emerge.
- Limited Client Involvement: The waterfall model employs a top-down methodology in which the customer is only involved in the early phases and the requirements are obtained at the beginning. Due to the lack of ongoing client interaction, the finished product may fall short of the customer’s demands or expectations.
- Late Testing and Feedback: In the waterfall approach, testing and feedback often happen toward the end of the development cycle. This may result in problems and flaws being discovered only after the fact, making correction more difficult and expensive. Iterative feedback loops and early problem discovery are crucial for successful software development.
- Failure: There is a high chance of project failure since the waterfall model counts on being able to identify and articulate every requirement up front. However, this is frequently not the case, and the likelihood of project failure rises if the initial specifications have sizable gaps or misunderstandings. Furthermore, there is a chance of creating the incorrect product entirely because the consumer is not involved until later phases.
- Limited Ability to React to Change: Market conditions and need changes can happen quickly in today’s corporate environment, which is rapidly changing. The waterfall model struggles with change because it is challenging to implement modifications once the development process has begun. By the time software is released as a result of this lack of adaptability, it may be obsolete or irrelevant.
When to use Waterfall Model?
The waterfall model is a software development model used in the context of large, complex projects, typically in the field of information technology. It is characterized by a structured, sequential approach to project management and software development.
The waterfall model is useful in situations where the project requirements are well-defined and the project goals are clear. It is often used for large-scale projects with long timelines, where there is little room for error and the project stakeholders need to have a high level of confidence in the outcome.
Every software developed is different and requires a suitable SDLC approach to be followed based on internal and external factors. Some situations where they can use of Waterfall model are as follows:
- Requirements are very well documented, clear, and fixed.
- Product definition is stable.
- Technology is understood and is not dynamic.
- There are no ambiguous requirements.
- Ample resources with the required expertise are available to support the product.
- The project is short.
In the next article, I am going to discuss the Spiral Model in Software Testing. Here, in this article, I try to explain Waterfall Model in SDLC. I hope you enjoy this Waterfall Model article.
About the Author: Pranaya Rout
Pranaya Rout has published more than 3,000 articles in his 11-year career. Pranaya Rout has very good experience with Microsoft Technologies, Including C#, VB, ASP.NET MVC, ASP.NET Web API, EF, EF Core, ADO.NET, LINQ, SQL Server, MYSQL, Oracle, ASP.NET Core, Cloud Computing, Microservices, Design Patterns and still learning new technologies.