RAD Model in SDLC

RAD model is Rapid Application Development model. It is a type of incremental model. In RAD model the components or functions are developed in parallel as if they were mini projects. The developments are time based and scheduled, delivered and then assembled into a working prototype. This can quickly give the customer something to see and use and to provide feedback regarding the delivery and their requirements.Developed to respond to the need to deliver system very fast. Methodology for compressing the analysis , design , build and test phases into a series of short , iterative development cycles. Usually In this model we use tools in development , such as requirement gathering tools, prototype tools , computer aided software engineering tools , testing tools etc.,Usually used with object oriented programming , such as java and c++.RAD generally uses time boring , where some features releases in order to complete the current version quickly. 

There are phases in this RAD model . 

• Business Modelling: Information flow is identified between various business requirements.
• Data Modelling: Information is gathered from business modeling is used to define data objects that are needed for the business
• Process Modelling: Data objects defined in data modeling are converted to achieve the business information flow to achieve some specific business objective. Description are identified and created for CRUD of data objects.
• Application generation: Automated tools are used to convert process models into code and the actual system.
• Testing and turnover: Test new components and all the interfaces.

Advantages:

• Time to deliver the end product is very less compared to other products.
• Changing requirements can be accumulated .
• Progress can be measured very easily
• Cycle time can be short with the use of powerful RAD tools.
• Use of tools and Frameworks. 

Disadvantages:

• Management complexity is more. 
• Resource requirement may be increased because it is very flexible to changes
• More budget is required as we use tools regularly.
• It is suitable for the system that are completely component based which are scalable. 
• Requires user involvement throughout the Life cycle.