Waterfall

Under the Waterfall methodology, each stage of development is performed sequentially, and each stage is completed before the next stage begins. The model assumes that each stage depends on the successful completion of the previous stage and does not involve returning to previous stages after they are completed.

Waterfall Key Stages:
1. Requirements definition: defining user requirements and project specifications.
2. Design: designing the structure and architecture of the project.
3. Development: creating and writing code.
4. Testing: testing and debugging of the created product, test operation.
5. Deployment: installation, configuration and launch of the created product, start of full-scale operation.

Like any methodology, Waterfall has its advantages and disadvantages. Its advantages include:
• A clear definition of project requirements and goals.
• Consistent milestones, which allows you to manage the process and monitor progress.
• Better organization and planning, which reduces risk and reduces uncertainty in the development process.
• Fixed timelines and budgets.

Disadvantages:
• Limited flexibility and ability to change during the development process. (the model has a mechanism for changes, but it leads to a complete recalculation of the budget and critically shifts the launch dates)
• Difficulties in managing and controlling the process when unexpected problems arise.
• Long development times and lack of quick feedback.

Waterfall is not the only approach to development today. However, it shows itself perfectly in projects with stringent requirements, where actual changes are rare and progress must be strictly controlled.