The Waterfall Model was the first SDLC Model to be introduced. It is also known as a "linear-sequential model". It is very simple to understand and use. In a waterfall model, whenever first stage over then and then only procedure goes to next stage.
In waterfall model, if tester found any bug, then he do not send product back to developer, Instead of doing that tester log the bugs, make reports and those bugs get fixed in next version of product.
In this model, the phases do not overlap. The progress is seen as flowing steadily downwards (like a waterfall) through the phases. The next phase is started only after the defined set of goals are achieved for previous phase and it is signed off, so the name "Waterfall Model"
When we use Waterfall Model ?
The folllowing points explain the use of waterfall model:
- When requirements are clear and fixed.
- When the project is short.
- When requirements are not chaniging frequently.
- When product definition is stable.
- When the risk is zero or minium.
Advantages of Waterfall Model:
These are some advantages of waterfall model:
- It is simple and easy to understand.
- It is easy to use and manage.
- It works for short and low budget projects.
- It is easy to arrange tasks.
- Process and results are well documented.
Disadvantages of Waterfall Model:
These are some disadvantages of waterfall model:
- High risks.
- Not good model for long project.
- Requirement changes can not accomodate.
- Poor model for complex project.
- Not desirable for project where requirement changes frequently.
