Addressing operator errors in supervisory systems

An investigation is given of human interaction with systems in which the user takes a supervisory role. These systems include process control, power generation, command and control, military and commercial aviation and medical life-support systems. Such systems share the properties of complexity, safety-criticality and the need to operate in a time-constrained environment. They also involve the pre-processing of data before the operator is given the information. Such systems occasionally fail in dramatic ways and such failures are usually blamed on `operator error´. However, the author argues that such failures are often due to characteristics of the system which arise as part of the engineering process and the way these characteristics are presented to the user. An analysis is given of such systems which relates the factors which may lead to operating accidents to three system components: the process under control, the human user or operator and the interface between user and process. It is proposed that by constructing the interface to present the salient task information given the behaviour of the process it is possible to reduce the complexity of the system as perceived by the user and thus reduce operating errors and improve overall system performance