Waterfall Model (traditional)
The Waterfall, or traditional phased, approach identifies a sequence of steps to be completed. Typically five developmental components of a project can be distinguished (four stages plus control):
Planning and design
Execution and delivery
Monitoring and controlling systems
Not all projects will have every stage, as projects can be terminated before they reach completion. Some projects do not follow a structured planning and/or monitoring process. And some projects will go through steps 2, 3 and 4 multiple times.
In our industry many organisations have adapted the Rational Unified Process (RUP) to fit this methodology. The Waterfall model works well for small, well defined projects, but often fails in larger projects of undefined and ambiguous nature.