In the 1970s, Brian Gallagher, Alex Balchin, Barry Boehm and Scott Shultz developed the Rapid Application Development approach with the aim of speeding up the previous, time-consuming software development process and making it more flexible.

Rapid application development only became famous a few years later. In the early 1990s, the British information technology consultant and author James Martin developed a method based on iterative development and the construction of prototypes.

To this day, the rapid application development approach is used in a variety of ways in the development environment. For example, the low-code platform Simplifier provides a technology that can be used to configure integrated applications in a resource-saving manner. Reusable modules and the use of existing IT systems ensure the necessary efficiency in the digitalization of company processes. Thanks to the rapid application development approach and rapid prototyping, Simplifier makes it possible to effectively develop a comprehensive and performance-oriented application in less time.

In the 1970s, Brian Gallagher, Alex Balchin, Barry Boehm and Scott Shultz developed the Rapid Application Development approach with the aim of speeding up the previous, time-consuming software development process and making it more flexible.

Rapid application development only became famous a few years later. In the early 1990s, the British information technology consultant and author James Martin developed a method based on iterative development and the construction of prototypes.

To this day, the rapid application development approach is used in a variety of ways in the development environment. For example, the low-code platform Simplifier provides a technology that can be used to configure integrated applications in a resource-saving manner. Reusable modules and the use of existing IT systems ensure the necessary efficiency in the digitalization of company processes. Thanks to the rapid application development approach and rapid prototyping, Simplifier makes it possible to effectively develop a comprehensive and performance-oriented application in less time.

Requirements planning
In the initial phase, designers, developers and users reach a rough agreement on the scope of the project and prioritize the application requirements so that prototyping can begin in future phases. Both developers and users are allowed to talk to each other and exchange ideas in the first phase. This is not done in the subsequent phases.

Based on the list of application requirements with prioritization, the developers design an executable prototype of the software as quickly as possible. In doing so, they can use a “software construction kit” with which the most important basic requirements can be quickly put together.

User Design
In the second phase, user feedback is collected after completion of the first prototype. The focus here is on defining the system architecture. Requirements are supplemented or refined. This allows initial modeling to be created. This step is repeated as often as necessary to further develop the project. In contrast to the first phase, the second phase is used more for a monologue by the user.

Construction
Once the basic user and system design has begun, the construction phase is where most of the actual application coding, testing and integration takes place. Along with the user design, the construction phase is repeated as often as necessary as new components are needed or changes are made to meet the requirements of the project. The new user requirements are optimized and added to the software in a short development cycle, usually between one day and up to three weeks. This approach results in new, improved versions of the software in each iteration.

Cutover
The final phase, the cutover, allows the development team to move the components to a live production environment in which any necessary tests or team training can be carried out.

The cyclical process clearly distinguishes rapid application development from the waterfall model. In the classic method of the waterfall model, each phase of development forms a separate unit. Once the respective unit has been completed, the next step is considered. As with a waterfall, it is no longer possible to return to a previous phase.

In contrast to the rapid application development approach, each step in the waterfall model is given a huge amount of time to avoid errors. As a result, software development is slower and can only take place with a great deal of time and energy. Errors in development or incorrect requirements can quickly cause a project in the waterfall model to fail.

While different forms of rapid application development emphasize slightly different concepts and design methods, the intensive use of prototypes is consistent across all forms. The use of prototypes enables a number of unique benefits throughout the development cycle:

User Involvement
Unlike a traditional waterfall model, where the design team discusses with users what features or implementations are required and has to plan specifications around these ideas, a RAD prototype allows users to use the software immediately. Feedback can be given on a live system and does not involve the abstract assessments of a design document.

Feasibility
Prototyping enables the development team to assess the feasibility of a particularly complex or risky component directly on site. By recognizing and working on complicated systems early in the development cycle, the software becomes more robust, less error-prone and better structured for future design enhancements.

Error reduction & debugging
With rapid prototype releases during a project, it is far more likely that errors can be detected and eliminated much earlier in the development cycle.