Rapid Application Model (RAD) model is one of the types of Software Development Life Cycle (SDLC). It is the methodology of developing the software, using incremental approach. It involves the development of all components, simultaneously, in the parallel processes, which, at a later stage, are integrated together, to form a prototype, so as to deliver it to the client and receive their reviews, in a quick time.
As the name suggests, this type of model is used to develop and deliver software product, quickly, in the minimal time. This model skips the detailed planning and initiates the working of software development process, as soon as requirements are gathered.
Methodology of RAD Model:
The basic working of the model consists of following activities, in the subsequent manner
- Gathering of requirements.
- Based on requirements, the process of developing the working prototype, for each component or functionality, is carried out simultaneously, in parallel.
- After being developed, prototypes are handed over to the client, so as to evaluate its working and accordingly, provide their reviews and feedback.
- On the perusal of feedbacks from the client, changes are brought to each prototype.
- The updated prototypes are then again delivered to the client, in order to re-evaluate them and provide the necessary feedbacks (if any).
- These activities are repeated iteratively, until no further necessary feedbacks are need to be considered.
Phases of RAD Model:
- Business Modelling
This phase involves the identification of all the significant information pertaining to business for the development of software products, by analysing the flow of information, among various business channels.
- Data Modelling
In this phase, all the information gathered during the business modelling phase, works as an input to output the defined sets of data.
- Process Modelling
Data sets prepared during the data modelling phase, works as the resource for this phase. These data sets are being transformed, to visualize & gain the flow of the information, pertaining to business process.
- Application Generation
This phase consists of development of prototypes, by making use of data and process, evolved during the data modelling and process modelling phase, with the help of automation tools.
- Testing and Turnover
Each developed components are tested, thoroughly along with the evaluation of all the interfaces.
Key Points of RAD Model:
- An incremental and iterative approach, involving the client or customer in the development process, ensuring quick delivery of the software.
- An alternative approach, to the traditional SDLC models, such as waterfall model, where it is a tedious & a hectic job to introduce major changes in the software product.
- It provides the advantage of code/component reusability and quick reviews of the product, directly from the clients.
- Effective for carrying out large projects, and is considered non-desirable for the small projects.
- This model is best to use, when the technical risks involved, are lesser and the software product, needs to be developed in the short span of time.
- As no detailed planning is done during the phase, thorough knowledge and understanding of the business or client requirements is desirable, to start the development process.
- Involvement of prototypes and client in the development process, results in lesser defects.
- It demands highly skilled developers.