A universal appointment rule in the presence of no-shows and walk-ins

Abstract

This study introduces a universal "Dome" appointment rule that can be parameterized through a planning constant for different clinics characterized by the environmental factorsâno-shows, walk-ins, number of appointments per session, variability of service times, and cost of doctor's time to patients' time. Simulation and nonlinear regression are used to derive an equation to predict the planning constant as a function of the environmental factors. We also introduce an adjustment procedure for appointment systems to explicitly minimize the disruptive effects of no-shows and walk-ins. The procedure adjusts the mean and standard deviation of service times based on the expected probabilities of no-shows and walk-ins for a given target number of patients to be served, and it is thus relevant for any appointment rule that uses the mean and standard deviation of service times to construct an appointment schedule. The results show that our Dome rule with the adjustment procedure performs better than the traditional rules in the literature, with a lower total system cost calculated as a weighted sum of patients' waiting time, doctor's idle time, and doctor's overtime. An open-source decision-support tool is also provided so that healthcare managers can easily develop appointment schedules for their clinical environment. © 2011 Production and Operations Management Society.