What is RAD Model? Phases, Advantages and Disadvantages

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Last Updated: 27 January 2021

What is RAD Model?

RAD Model or Rapid Application Development model is a software development process based on prototyping without any specific planning. In RAD model, there is less attention paid to the planning and more priority is given to the development tasks. It targets at developing software in a short span of time.

SDLC RAD modeling has following phases

Business Modeling
Data Modeling
Process Modeling
Application Generation
Testing and Turnover

Rapid Application Development Model — RAD Model Diagram

It focuses on input-output source and destination of the information. It emphasizes on delivering projects in small pieces; the larger projects are divided into a series of smaller projects. The main features of RAD modeling are that it focuses on the reuse of templates, tools, processes, and code.

Different Phases of RAD Model

There are following five major phases of Rapid Application Development Model

RAD Model Phases	Activities performed in RAD Modeling
Business Modeling	On basis of the flow of information and distribution between various business channels, the product is designed
Data Modeling	The information collected from business modeling is refined into a set of data objects that are significant for the business
Process Modeling	The data object that is declared in the data modeling phase is transformed to achieve the information flow necessary to implement a business function
Application Generation	Automated tools are used for the construction of the software, to convert process and data models into prototypes
Testing and Turnover	As prototypes are individually tested during every iteration, the overall testing time is reduced in RAD.

When to use RAD Methodology?

When a system needs to be produced in a short span of time (2-3 months)
When the requirements are known
When the user will be involved all through the life cycle
When technical risk is less
When there is a necessity to create a system that can be modularized in 2-3 months of time
When a budget is high enough to afford designers for modeling along with the cost of automated tools for code generation

Rapid Application Development Advantages and Disadvantages

Advantages of RAD Model	Disadvantages of RAD Model
Flexible and adaptable to changes	It can't be used for smaller projects
It is useful when you have to reduce the overall project risk	Not all application is compatible with RAD
It is adaptable and flexible to changes	When technical risk is high, it is not suitable
It is easier to transfer deliverables as scripts, high-level abstractions and intermediate codes are used	If developers are not committed to delivering software on time, RAD projects can fail
Due to code generators and code reuse, there is a reduction of manual coding	Reduced features due to time boxing, where features are pushed to a later version to finish a release in short period
Due to prototyping in nature, there is a possibility of lesser defects	Reduced scalability occurs because a RAD developed application begins as a prototype and evolves into a finished application
Each phase in RAD delivers highest priority functionality to client	Progress and problems accustomed are hard to track as such there is no documentation to demonstrate what has been done
With less people, productivity can be increased in short time	Requires highly skilled designers or developers