Analysis of patient-mover dispatching and equipment-marshalling areas: a simulation study at the University of Michigan Hospital.

We study the intra-facility patient movement problem in large, multi-floor hospitals, where many patients are moved each year by patient movers using wheelchairs or gurneys. Using a simulation model, and the University of Michigan Health System (UMHS) hospital as the problem setting, we compare alternative rules for dispatching the patient movers via a centralised, computer-controlled system. Included in the comparison is the rule used currently at the hospital as well as new alternative dispatching rules we develop for the study. Our results suggest that significant improvements in system performance can be obtained by using better dispatching rules that consider not only the proximity of the patient mover to the patient pick-up point but also the type of equipment needed (wheelchair versus gurney) and the location of the equipment marshalling areas, which also play a key role. In conjunction with the dispatching rules, we investigate the number and location of the marshalling areas, and show empirically that carefully locating them based on usage improves the system performance as much as, if not more than, a more efficient dispatching rule. Although the UMHS hospital serves as the problem setting, our study would apply to most hospitals with dedicated patient movers and centralised dispatching.