2. ο Waterfall method is also known as Linear sequential
life cycle model.
ο In this method, each phase need to be completed
before it proceeds to next phase.
ο At the end of each phase, a review takes place to
determine if the project is on the right path and
whether to continue or discard the project.
ο In this model the testing starts only after the
development is complete.
ο In waterfall model phases do not overlap.
4. Advantages
ο This model is simple and easy to understand and use.
ο It is easy to manage due to the rigidity of the model β
each phase has specific deliverables and a review
process.
ο In this model phases are processed and completed one
at a time. Phases do not overlap.
ο Waterfall model works well for smaller projects where
requirements are very well understood.
5. Disadvantages
ο Once an application is in the testing stage, it is very
difficult to go back and change something that was not
well-thought out in the concept stage.
ο No working software is produced until late during the
life cycle.
ο High amounts of risk and uncertainty.
ο Not a good model for complex and object-oriented
projects.
ο Poor model for long and ongoing projects.
ο Not suitable for the projects where requirements are at
a moderate to high risk of changing.
6. When to use the waterfall model:
ο This model is used only when the requirements are
very well known, clear and fixed.
ο Product definition is stable.
ο Technology is understood.
ο There are no ambiguous requirements
ο Ample resources with required expertise are available
freely
ο The project is short.