Rapid Application Development is a method of producing finished, useable systems quickly. Generally it will aim to run within a 6 month period, however 3 months is considered to be the ideal. The RAD method has four stages in its life cycle:
- Requirements planning phase – This is where the research into the system to be developed (or replaced) is carried out in order to establish the end user requirements for the new system, including interviewing the end user clients and systems analysis consistent with your chosen methodology. The preparations for the JRP* (joint requirements planning) sessions are also made and the JRP workshop is conducted.
- User design phase – The JAD (joint application development) workshops are prepared and are started. The system design is started. The JAD designs and initial prototypes are consolidated for usability tests. The results of these tests form the second JAD workshops which are then consolidated into the finalized design.
- Construction phase – The SWAT team is developed and tested. The documentation is prepared and finalized, and the end user training is also prepared and undertaken. Cutover preparation is begun.
- Cutover – This has the final testing and finalizing product with end users.
Another major feature of RAD is prototyping, using powerful development tools to facilitate quick screen design (for use in JAD) and also to allow automatic code production. These prototypes will evolve into the final system with the use of stepwise refinement and also allow for quick changes and bug fixes. The prototype also encourages the user to make valued contributions earlier as they can see the system that is being developed for them. RAD takes great pains to discover and eliminate bugs as early as possible. The longer they are allowed to remain in the system then the more time needed to eliminate them. Many RAD developments (including the modifed version used by Microsoft) have a ‘daily build’ policy, which means that everyone has an up to date copy of the system as it evolves. The testers can therefore quickly catch bugs as they are introduced into the system.
A system being developed by RAD must have an experienced Analyst conducting the phases. This applies more so to the User design phase – a JAD professional would be necessary. The method can save huge amounts of money if implemented correctly, and fail to develop a system suitable for the user if not.
* JRP – This is almost a brain storming session intended to produce various objectives, functions and issues.
- System objectives.
- Details of possible system functions. (listed, benefits, estimate of the return on investment of the function,
- Prioritising of the functions)
- Decomposition diagram of the system
- Process flow diagram
- Flow diagram showing interfaces with other systems
- Unresolved issues – responsibility and deadline for issue, details of assignment for resolution of issue (date assigned, date for completion)