Rapid Application Development (2.1.j)
Rapid Application Development is a more modern software design strategy (in comparison to the traditional waterfall and spiral models). It involves consulting the user after a number of prototypes (normally with reduced functionality) have been built, as well as during the analysis process, and using the results of the consultation to influence the next prototype. They can then add any modifications as the solution develops.
The process continues until both the user and the developer are happy with the solution. This allows the user to actually see the project evolving and add new features if they decide on them later without excessively increasing the cost and the time frame.
The overall development time using RAD is often quicker than an equivalent project using the Systems Development Lifecycle.