Software Development Life Cycle (SDLC) Models: Waterfall Model
The Waterfall Model is one of the earliest and most widely known software development life cycle models. It is a linear and sequential approach to software development, where progress is seen as flowing steadily downwards (like a waterfall) through several phases.
The Waterfall Model consists of the following phases:
- Requirements Analysis: In this phase, the requirements for the software system are gathered from the stakeholders. This involves understanding the needs of the end-users and documenting them in a detailed requirements specification document.
- System Design: Once the requirements are gathered, the system design phase begins. In this phase, the overall architecture of the system is designed. This includes defining the software architecture, database design, and any other necessary technical specifications.
- Implementation: The implementation phase involves the actual coding of the software based on the design specifications. Developers write code according to the requirements and design documents prepared in the previous phases.
- Testing: Once the implementation is complete, the software is tested to ensure that it meets the specified requirements and functions correctly. This includes both functional testing to check if the software performs its intended tasks and non-functional testing to evaluate aspects like performance, security, and usability.
- Deployment: After successful testing, the software is deployed to the production environment. This phase involves installing the software on the end-users' systems and making it available for use.
- Maintenance: The final phase of the Waterfall Model is maintenance. In this phase, any issues or bugs discovered after deployment are addressed, and updates or enhancements to the software are made as needed.
One of the key characteristics of the Waterfall Model is its strict linear progression from one phase to the next. Each phase must be completed before moving on to the next, and there is little room for iteration or changes once a phase is complete.
While the Waterfall Model provides a structured approach to software development and is easy to understand and manage, it has some limitations. One of the main criticisms of the Waterfall Model is its inflexibility in accommodating changes to requirements or design during the development process. Since each phase is dependent on the deliverables of the previous phase, making changes later in the development cycle can be time-consuming and costly.
Despite its drawbacks, the Waterfall Model can still be suitable for projects with well-defined requirements and stable technologies. However, in today's dynamic and rapidly changing business environments, many organizations prefer more flexible and iterative approaches to software development, such as Agile or DevOps.