Reducing Disruptive Effects of Service Interruptions in Appointment Scheduling

This paper considers appointment scheduling for outpatient services when the service of scheduled patients can be interrupted by emergency arrivals. We consider a single doctor who consults K patients during a fixed-length session. Each patient has been given an appointment time during the session in advance. Our evaluation approach aims at obtaining accurate predictions at a very low computational cost for the waiting times of the patients and the idle time of the doctor. To this end, we investigate a modified Lindley recursion in a discrete-time framework. We assume general, possibly distinct, distributions for the patient’s consultation times and allow for individual no-show probabilities. This fast evaluation method is then used in a local search algorithm to provide insights into scheduling with service interruptions. Numerical examples show that this method outperforms simulation optimization and naive approaches in terms of cost and running time.