Simulation analysis of appointment scheduling in an outpatient department of internal medicine

Long waiting times for treatment in the outpatient department of internal medicine, followed by short consultations has long been a complaint of patients. This issue is becoming increasingly important in Japan with the progressively aging society. In this context, a discrete event simulation model to examine various appointment schedules in a mixed-patient type environment in an outpatient department of a general hospital was developed. A special purpose data generator was designed to validate the model and to conduct experiments in bottleneck situations at consultation rooms in the existing system. Some efficient appointment schedules (ASs) were identified, which drastically reduced patient waiting time while keeping doctor idle time as low as possible without adding extra resources. The sensitivity of performance was examined under three realistic environmental factors: no show, variance of consultation time, and variation of walk-ins.