Psychophysiological assessment of human reliability in a simulated complex system.
Stress-strain processes affect human reliability in operators in control of highly automated systems. Job demand and decision latitude play an important role in the modification of these processes. Objective methods of task analysis involving the study of 50 operators controlling an electroenergy network were used to define three "typical' tasks. The present study was carried out at simulated computer work places with the same equipment and the same relations of information transfer as in the work settings. During the 3-h activity HR, BP and motor activity were recorded with an ambulatory monitoring system. The operators answered questions concerning subjective strain, emotion, motivation, perceived control, and success by means of a pocket computer. The study revealed marked increases in strain with increasing job demand and increased decision latitude. The results partly contradict Karasek's (1979) model. The operator in a dyadic team having decision authority showed significantly higher systolic blood pressure, heart rate, and self-reported strain compared to the co-operator. Human reliability cannot be increased by means of increasing decision latitude in order to enrich the job. It is suggested that human reliability can be improved by spreading decision authority over the whole team. Further psychophysiological investigations will be necessary, testing not only Karasek's but also alternative assumptions for the design of complex systems in order to reduce strain and boredom induced decrements in human reliability.
Rau
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Technische Universität Dresden, Fakultät für Naturwissenschaften und Mathematik, Institut für Arbeits- und Organisationspsychologie und Sozialpsychologie, Germany.
D000328:Adult; D001143:Arousal / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D003198:Computer Simulation; D003657:Decision Making / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009043:Motor Activity / Q000502:physiology; D011603:Psychophysiology; D013315:Stress, Psychological / Q000150:complications; D016526:Workload / Q000523:psychology*