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Waterfall

Waterfall

Waterfall is the traditional and oldest software development methodology that defines a sequential approach to project development. Here, development stages follow one another sequentially, similar to a cascade, and each stage has its own tasks and deliverables that must be completed before moving on to the next one.

Stages

The main Waterfall stages include:

  1. Requirements Analysis. At this stage, all requirements from the client for the software product are gathered: business needs analysis, functional and non-functional requirements. Project documents are also created here.
  2. System Design. Here, the system architecture, database structure, and user interface details are developed.
  3. Implementation. This is the stage during which the software product is developed based on the project documents.
  4. Testing. Here, the application is tested to identify errors and defects, for example, unit testing, integration testing, and system testing.
  5. Deployment. After successful testing, the application is deployed to the users' working environment.
  6. Maintenance. At this stage, support and bug fixes are provided after deployment.

Pros and Cons

Pros of the Waterfall model:

  • Simplicity and structure. The model is easy to understand and use because development stages follow one another sequentially, which simplifies project planning and execution.
  • Requirement stability. Requirements are fixed at the beginning of the project, and changes to them are limited, which helps avoid frequent revisions during development.
  • Easy progress assessment. Due to the sequential nature of the model, it is easy to determine project progress and its adherence to the schedule and budget.
  • Documentation. Each stage is accompanied by the creation of documents, making it easy to hand the project over to other teams or developers if needed.

Cons of the Waterfall model:

  • Limited flexibility. The model does not allow for easy changes in development at later stages, which can cause problems if requirements change.
  • Risk of client misunderstandings. If requirements were not properly defined at the beginning of the project, misunderstandings between developers and the client may arise.
  • Long development cycle. The Waterfall model is often time-consuming, especially for large and complex projects, since each stage must be completed before moving to the next one.
  • Low adaptability to change. If unexpected problems or changes arise, the Waterfall model may be ineffective in handling such situations.
  • No real product until completion. Users do not have the opportunity to test and use the actual product until all stages are finished.

When is Waterfall best used?

This model is best suited for projects where requirements are stable and changes are unlikely. For example, database management or other well-defined systems where high stability and reliability are required.