Distance restricted maximal covering model for pharmacy duty scheduling problem

Abstract

Pharmacies are considered as an integral part of health care systems for supplyingmedicine to patients. In order to access medicine with ease, pharmacies locationsin the context of distance and demand are important for patients. In the case of afew numbers of pharmacies may be on duty at nights or during holidays,pharmacies duty scheduling problem occur and can be associated with locationmodels. In contrast to widely used p-median model which aims to minimize thedemand-weighted distance, we maximize the demand covered over the distancebetween the patients and the pharmacies on duty. Main contribution of theproposed model is the restriction constraint for the distance between pharmacieson duty in order to ensure fairness in an organizational view of point. We proposea distance restricted maximal covering location model (DR-MCLM) in this study.This mathematical model is a mixed integer linear programming model and solvedby Lingo optimization software. The distances between the pharmacies and thesites are obtained using Geographic Information Systems (GIS). The model isapplied for the case in Adana, one of the biggest cities in Turkey. The results aregiven on the maps of the city, including the pharmacies on duty and theirassignments to sites in each day of the period.