ABSTRACT

Ergonomic approaches to the evaluation of operator’s fitness to work have typically assumed that the functional characteristics of the operator (e.g. knowledge about task, skill level, information processing capacity, etc.) are invariant. They are assumed to not be influenced by variables such as operator mood state, sleep history, time on task, etc. Research efforts aimed at enhancing the safety and reliability of complex process plant operations have, as a result, focused on the improvement of the technical skills of the operator, as well as by reducing operator requirements by automating processes. In complex technological systems, human involvement in the production of accidents is estimated at between 40 and 60% (power plants) and up to 80% (aircraft accidents). This testifies to the inadequate evaluation of operator efficiency by existing techniques. The monitoring of an operator’s physiological parameters during his professional life known to be related to effective skill utilization can be used to enhance system performance. While the requirements for professional knowledge and skills may be defined for various kinds of physical and mental work, the evaluation of their functional state over time suffers from a failure to take into consideration not only levels of psychophysiological parameters, but also changes of state of the operator, especially those occurring over different periods of time (year to year, day to day variation, within work schedule variation,

variation produced by changing shifts, etc.). The direct or indirect measurement of psychophysiological changes allows for the evaluation of the structure (or moment to moment state of the operator) of the functional state of the operator, allowing us to predict individual fitness and reliability of the operator for effective work.