Cognitive capability versus system complexity in electronic maintenance

Diagnostic behavior is strongly influenced by the interaction between the diagnostician and the failed equipment. Previous research resulted in a model of diagnostic behavior that predicts repair time distributions and expected values. In this work the relationship between expected value of repair time, equipment complexity, and human cognitive limitations is developed. Specifically, it is shown that if equipment complexity, as measured by degree of interconnectedness of components, exceeds normal human cognitive limitations, then some proportion of equipment failures will be nondiagnosable.