Answer:
Phases of waterfall model are Requirement analysis system design implementation testing, deployment maintenance.
Explanation:
Waterfall model should be chosen when the requirement is fixed. It is not suitable for rapid development as well for the requirement which keep on changes.
Even the technology should not be dynamic. This also expects the project should be short. Another disadvantage is that it is difficult to measure the progress within stages.
It is not suitable for object-oriented projects. Here the process is completed phase by phase and one at a time.
