Using simulation to improve outpatient appointment system with minimum change

As a result of population aging in Japan, health care has become the focus of the society. As an essential quality measure, the outpatient waiting time has to be dealt well with. an effective appointment system plays an important role in controlling outpatient waiting time. In our case, the current waiting time is not shorter than the normal level of the country. And since it is expensive and risky to upgrade the entire appointment system at one time, the less modification the solution requires the easier it will be accepted. As a result, the purpose of this study is to reduce outpatient waiting time with minimum change of the current system. In this paper, a simulation model for the clinic in the 1st Internal Medicine Department was developed to examine various classical appointment patterns and a pattern created by optimization tool. The results show that the appointment pattern is a leverage of the current system. By only optimizing it, the proposed appointment pattern could reduce outpatient waiting time by 38% on average without adding a single resource. Furthermore, by the study of other clinics with the same method, patient's arrival process is considered to be the most factors for choosing those patterns.