A complete, detailed requirements analysis is done that attempts to capture the system requirements in a Requirements Specification. This is followed by a complete system design and then development and testing. The elapsed time between the initial analysis and testing is usually a period of several months. RAD is a methodology for compressing the analysis, design, build, and test phases into a series of short, iterative development cycles. This has a number of distinct advantages over the traditional sequential development model.
Iteration allows for effectiveness and self-correction.
Studies have shown that human beings almost never perform a complex task correctly the first time. However, people are extremely good at making an adequate beginning and then making many small refinements and improvements. We should encourage and exploit this rather than fight it. RAD projects are typically staffed with small integrated teams comprised of developers, end users, and IT technical resources. Small teams, combined with short, iterative development cycles optimizes speed, unity of vision and purpose, effective informal communication and simple project management.