Using discrete event simulation to evaluate housestaff work schedules

A discrete-event simulation model of work performed by hospital interns and residents was developed. The model incorporates such complex features as interruptions of one activity by another, involved decision processes by mobile resources, and highly variable work arrival processes. Where historical data were lacking and too expensive to collect, surveys of experts produced sufficient information to use the VISIFIT distribution fitting package to specify input processes. Validation efforts showed that the model accurately predicted the results of changes to the schedule. With its validity established, the model has since been used to investigate the ramifications of alternative systems, including the addition of a night-float team and more help from subspecialty fellows. The consequences of changes in patient load or decreased availability of senior students were also examined. The prospect for regulatory or legislative restrictions on housestaff hours make the model a valuable tool for evaluating scheduling rules and plans