A study on human redundancy in execution of computerized emergency operating procedures

This study examined the effects of human redundancy arrangements on performance in the execution of computerized emergency operating procedures. It was found that there was significant difference in completion time but no significant differences in error rate or subjective workload between single-operator and two-operator setups. For the two-operator setup, an unbalanced workload was found. Team completion time was significantly lower than the higher and averaged completion times of individual operators, but was not significantly different from the lower completion time of individual operators. The higher error rate of individual operators was significantly higher than the team error rate, but there were no significant differences between the team error rate and the lower and averaged error rates of individual operators. These findings indicate the complex nature of human redundancy when using digital systems.