(第3空)The traditional model for systems development was that an IT department used ( )which is a process-centered technique, and consulted users only when their input or approval was needed.Compared with traditional methods, many companies find that JAD allows key users to participate effectively in the ( ).When properly used, JAD can result in a more accurate statement of system requirements, a better understanding of common goals, and a stronger commitment to the success of the new system. RAD is a team-based technique that speeds up information systems development and produces a functioning information system. While the end product of JAD is a(an) ( ),the end product of RAD is the ( ).The RAD model consists of four phases. During the ( ),users interact with systems analysts and develop models and prototypes that represent all system processes, outputs, and inputs.