RAD or rapid application development is a recent methodology introduced in the field of software development. Big institutes and software firms such as Microsoft, IBM and so on still rely on the slow paced traditional software development methodologies for the development of their software products.
However, the benefits of the rapid application development methodology cannot be overlooked when it comes to the development of the larger and urgently required software products. “Rapid application development employs the idea of rapid prototyping rather than minimal planning”.
We can say that the writing and designing of the code are somewhat inter-weaved in rapid application development methodology. Since there is a lack of pre-planning like in other software development methodologies it is quite easy and fast to make changes in the requirements of the software system or application.
What is Rapid Application Development?
There are two things are exclusively involved in the process of rapid application development:
1. Iterative development and
2. Software prototyping
– Rapid application development model operates on various prototyping techniques and structured techniques such as data driven information engineering and thus accelerates the process of the development.
– In addition to this another purpose is served by the prototyping and structured techniques which is that they help in defining process of the user’s requirements.
– Rapid application development model was officially first employed in the year of 1970.
– Rapid application development model was developed in a response to the slow paced traditional development methodologies prevalent at that time.
– It was so because before software system or application could be developed completely its user requirements would incur some changes.
– This would either devoid the software of some functionality or might make the system unfit for use.
– The rapid application development has known to suffer from an assumption made by most of the programmers.
– The methodical requirements analysis would suffice for the identification of all the requirements including the critical requirements.
Phases of Rapid Application Development
Rapid application development model comprises 4 main phases:
1. Requirements planning phase:
– In this phase the rapid application development methodology insists on the combination of the system analysis phases and system planning phases of the SDLC (software development life cycle).
– This phase also involves an amiable discussion among the IT staff members, managers, users regarding the scope of the project, business needs, system requirements, and constraints and so on.
– It ends with the management getting the authorization to continue with the development.
2. User design phase:
– This phase involves an interaction among the users and the system analysts performing operations on the inputs, outputs via the system processors.
– Rapid application development model puts the following two techniques in to a combination for the translation of the user needs in to working models:
a) JAD or joint application development techniques and
b) CASE tools
– The interaction here is continuous thus allowing the users to modify, understand and finally approve a model of the software system that works and meets all their needs.
3. Construction phase:
– This stage is more focused up on the application and program development task just as in the software development life cycle.
– But the difference here is that in RAD the participation of the users never stops and thus there are frequent suggestions for improvements and changes with the development of the actual reports. Basically the tasks involved are:
b) Application development
d) Unit integration
e) System testing
4. Cut over phase:
– This is the last stage and somewhat resembles the last activities of the software development life cycle too. Similar tasks are:
a) Data conversion
c) Change over to the new system
d) User training
– The entire process is not as expanded as the traditional methods but is rather compressed.
– This results in the production of a system that is built and delivered much sooner. Tasks involved are:
a) Data conversion
b) Full scale testing
c) System changeover
d) User training