Rapid application development (RAD) features aspects of iterative development and prototyping, focusing on rapid construction of prototypes to test out ideas and move the project forward, rather than spending a lot of time in the planning stage. In essence, the planning of the software is merged with the writing of the software, as planning and coding follow each other in a cyclical nature.
Of course, some roadmaps for the software exist. It's just that the pre-planning is minimized and, while the overall plan is followed, the path to get there may change during development. With the initial plan established, prototypes are created and used to dictate the plan for the next batch prototypes. This continues until the project is finished.
A chart of the RAD process is shown in the following diagram The initial planning stage moves into a development/design-plan cycle.
When the project is complete, it is cut over into the next phase, which may be testing, deployment, or another aspect of the overall project:
