To enable efficient and safe interaction between man and machine, man must be taken as a model for the entire `man-machine system'. Here, psychology can be of help. New technologies require that attention to physical and psychophysiological controlling tasks be augmented with concerns for cognitive interaction and interfaces. The man-machine interface has changed. Automation has given the human operator the role of supervisory control. His main task has become to find solutions in new and unexpected situations. In this paper, the author describes a model of human problem solving, or human performance in general. But this `Generic Error-Modellng System' of GEMS can also be used as a directive for the analysis, design and evaluation of the whole man-machine system. In terms of the model man's activities have moved to the `knowledge-based' level of functioning. The author further analyses the difficulties in human performance with respect to his new role, as well as other contributing factors to accidents in complex environments.
Abstract