Task network modeling: resolving manning issues in complex environments

Limitations that humans impose on task execution are rarely integrated into simulations of complex systems, resulting in loss of outcome fidelity. A discrete-event simulation tool has been used to model the impact of human interactions in US Navy and Coast Guard vessels. Models for these vessels have been used to estimate workload and fatigue. In workload measuring applications detailed task networks for teams of individuals were modeled over the 14-day scenarios. Predictions of operator utilization for several manning configurations were used to optimize manning and task allocations for the team. Models predicting fatigue were developed for entire crews to estimate the impact of work and sleep schedules over the same 14-day period on individual fatigue levels. Used in combination, these models provide predictions of the appropriate team size needed to maintain that watch level around the clock for a sustained period of time.