Waterfall - DavidMyrseth/BuketovPY GitHub Wiki

Waterfall is one of the traditional software development models that follows a linear and sequential process. In this model, each phase must be completed before moving on to the next. It is called "Waterfall" because the process flows downward like a waterfall, with each phase cascading into the next.

Key Phases of the Waterfall Model:

  1. Requirements Gathering: During this phase, all the requirements for the system are collected and documented. These could be functional and non-functional requirements.

  2. System Design: In this phase, the architecture of the system is designed. Technologies are selected, tools are chosen, and a detailed system design is created.

  3. Implementation (Coding): Programmers begin writing code based on the design. This is the main phase where the system is built.

  4. Testing: After the code is written, the system undergoes testing. Bugs are identified, and it is checked whether the system meets the specified requirements.

  5. Deployment: Once the system passes testing, it is deployed and handed over to users or clients.

  6. Maintenance: After deployment, the system may require updates, bug fixes, and adjustments based on user feedback and real-world use.

Advantages of Waterfall:

  • Clarity and Predictability: Since each phase has clear and fixed goals, projects can be planned and assessed easily.
  • Documentation: The Waterfall process is usually highly documented, making it suitable for large, long-term projects with multiple stakeholders.
  • Structured Process: Each phase follows a strict order, making project control and management easier.

Disadvantages of Waterfall:

  • Lack of Flexibility: A major drawback is the inability to respond to changes easily. If new requirements arise, they are difficult to incorporate without revisiting and revising the entire project.
  • Late Error Detection: Errors are often discovered only during the testing phase, making them harder and more expensive to fix.
  • Limited User Interaction: The Waterfall model generally doesn’t involve users actively during the development process, which can lead to a final product that doesn’t fully meet their needs.

When to Use Waterfall:

The Waterfall model works well for projects where the requirements are well understood from the beginning and are unlikely to change during development. It is suitable for large, complex, or standardized systems where stability and predictability are a priority. Examples include large enterprise applications or government projects.

However, with the rise of Agile methodologies, the Waterfall model is less frequently used for dynamic or rapidly changing projects, where requirements are likely to evolve over time.