A Double Edge Sword: Compensatory Behavior in Coping with System Malfunctions

Abstract

Malfunctions and minor technical problems in system operation are not a rare event when humans interact with engineering systems. When a problem is detected, the system should, in principle, be halted and repaired. Often, however, operators decide to continue their work and adopt alternative modes of behavior that bypass or compensate for the malfunctions. We label this type of responses “compensatory behaviors”. They are adopted because the operator judges them to be less costly than the costs involved in stopping and repairing the system. Twenty Subjects, had four sessions of training, with a simulated filling work station in a chemical plant, where 8 simultaneous tanks had to be filled with lethal solutions. Malfunctions in the automatic filling regulator of one of the tanks, occurred intermittently, resulting in two types of risks: a high risk failure could explode the entire system at the cost of 200 points; a low risk failure could lead to a defective container, translated to a loss of 10 points. Subjects could resolve to shut down the station for repair at the cost of 100 points, or switch the failed tank to manual and stop the filling when the liquid reached the required volume. Their ultimate goal was to achieve the highest score possible. Results showed significant preference for compensatory behavior over repair, in all stages of skill acquisition and at all levels of potential risk. When adopting compensatory behavior, subjects' decision, attention and main efforts seem to have been exclusively guided by their ability to avoid the occurrence of explosions. The number of explosions was indeed reduced, although not eliminated, with training. At the same time, and in contrast with their belief, subjects slowed down their production rate, had more errors and more defective containers. Thus the total cost of compensatory behavior was higher than the costs of repairing the system. This is the double edge sword of compensatory behavior. The selective focus on direct costs and the neglect of indirect costs, have important implications to decision behavior research and skill acquisition, as well as practical implications to the development of training programs and work procedures.