The RAD(Rapid Application Development) model is the software developing model that thefunctions are developed in parallel. In other words, they divide the projectinto smaller segments and the segments are developed as if they are miniprojects. The RADmainly focuses on the prototype building. The codes for the software are mainlydeveloped by the automated code generators.
The RAD isdeveloped in 1991 by James Martin. And it is one of the most populardevelopment life cycles. There are five steps in RAD. They are – 1) Business Modelling2) Data Modelling3) Process Modelling 4) Application generation 5) Testing and turnover Step 1: BusinessModelling Business modeling is the firststep of the RAD. In this step, the information needed for developing thesoftware is collected from the various fields and resources.
After that, thebusiness function are identified and combined to make a useful description ofhow the information will be used. The users come and preview the informationcollected and agree on project scope and the requirements. The JAD (JointApplication Development) meeting is done in this step.Step 2: Data Modeling The information collected in thefirst step are analyzed and converted to the data objects. The data objects arethe information that are grouped in different groups that will be later used inthe software development. And the relationships between these groups aredefined. Each group with the same data information are analyzed and a cleardescription is given to every group.Step 3: ProcessModeling The dataobjects in the step 2 (data modeling) are converted to useful information touse in the software development.
In this step, changes, removing andmodifications of the data objects are done and more data objects can also bedefined. Step 4: ApplicationGeneration This step iswhere the information and the data objects are generated to codes with theautomation tools. And the data models are turned into the prototypes.in thisstep too. The prototypes are created because they will be used to test in thenext step.Step 5: Testing andturnover The testing of the interfacesand components are done in this step. The prototypes created are tested and the datamodels are tested one by one. The good point is that the components are alreadytested in the previous steps so there is hardly no big problems.
When to use RAD model? RAD modelshould be used in the following conditions. 1) When there is not much time limit and need todeliver the project in 2 or 3 months. 2) When there will be many changes to the prototypemodel throughout the software developing. 3) When the requirements for the business isperfect and there is many knowledge about business system. 4) When the budget is high and can afford to usethe automated code generators. 5) When there are enough developers and designersto develop (quickly)Advantages of usingRAD The advantages of using the RADmodel is as follows. 1) The working system is divided into smallsegments so the work rate is done quickly.2) The user communication is in the important partso there is always feedbacks from the customers and can avoid the errors and misunderstandingsin software developing.
3) The codes for the RAD model can be reusable soit saves time. 4) The JAD meeting is done in the first step andall the functions are defined so there are hardly errors in the further steps.5) All requirements are not needed in one time, thesoftware development can be done even if there is little requirements about thesystem. (But that requirement must be perfect)Disadvantages ofusing RAD The disadvantages of using theRAD software is as follows.
1) It needs a lot of developers and designers sincethe projects have to be finished in little time. 2) Also needs the great skilled developers anddesigners to finish projects quickly.3) Expensive to use the automated codes4) After the JAD meeting, the requirements cannotbe fixed anymore.
5) The time limit is very little so if the userwants to change something, it cannot be done. Theuser must be the one who can attend all the meetings