ABSTRACT
In the traditional systems development process, a system is built to solve an operational problem, and the functions of the system (what the system does) and the operational logic of the system (how the system does what it does) are defined according to the engineering requirements. The user interface is typically defined toward the end of the development process. Because the functions and operational logic of the system have already been defined, the interface must then build a bridge between how the user thinks about the task and how the system was designed to operate. This requires the user to learn the system’s functions and operational logic; when the user must perform a task using the system, he/she must first decide which system functions are appropriate to accomplish the task, then apply the appropriate procedures (based on the operational logic) to use those functions. For a complex system, this can require extensive training requirements and may cause errors during system operation.
