A process computer's contribution to the reduction of mental effort and to the handling of systems malfunctions

Abstract

The information functions performed by an operator in charge of a continuous process operation are compared for conditions with and without computer assistance. The operator's mental contribution is studied in the context of a model of integrative behavior which considers the information functions which take place in the individual's communication channel. The amount of information, in the Information Theory sense, which is transmitted in the performance of mental therbligs, is compared for two modes of operation—automatic control with and without computer assistance. The comparison entails a consideration of the total entropy displayed by the system and the operator's information processing rates for various operating conditions. The role of the computer is discussed when information surges due to systems malfunctions occur. Response times are proposed as important measures of system's worth. In certain instances, response times are shown to increase with system's complexity and the case is made for adding auxiliary systems, including process control computers, which would be designed in such a way so as to handle the information overloads which occur during emergencies.