JAD is a requirements-definition and user-interface design methodology in which end-users, executives, and developers attend intense off-site meetings to work out a system's details. So the Joint Application Development (JAD) methodology aims to involve the client in the design and development of an application. This is accomplished through a series of collaborative workshops called JAD sessions. Two employees of IBM, Chuck Morris and Tony Crawford, developed the JAD methodology in the late 1970s and began teaching the approach in to the 1980s.
JAD focuses on the business problem rather than technical details. It is most applicable to the development of business systems, but it can be used successfully for systems software. It produces its savings by shortening the elapsed time required to gather a system's requirements and by gathering requirements better, thus reducing the number of costly, downstream requirements changes. Its success depends on effective leadership of the JAD sessions; on participation by key end-users, executives, and developers; and on achieving group synergy during JAD sessions.
In contrast to the Waterfall approach, JAD is thought to lead to shorter development times and greater client satisfaction, both of which stem from the constant involvement of the client throughout the development process. On the other hand, with the traditional approach to systems development, the developer investigates the system requirements and develops an application, with client input consisting of a series of interviews.
Rapid application development (RAD), a variation on JAD, attempts to create an application more quickly through strategies that include fewer formal methodologies and reusing software components.