A two-echelon model for the location-routing problem: distribution of Covid-19 vaccines

Abstract

Vaccination studies against the Covid-19 virus, which has affected our country and the whole world, bring along a major logistical problem for the mass vaccination of the modern world. Various vaccines produced by different methods such as mRNA and inactive virus method are made ready for mass production by companies. A well-planned distribution network is important for these vaccines with different shelf life under different conditions. In this study, the two-echelon location-routing model that will efficiently use the shelf life for Covid-19 mRNA vaccines, which are used in our country and need harsh storage conditions, is emphasized. In this respect, hubs and centers were determined with two different methods, and then time-limited capacitated vehicle routing problem mathematical model was developed for vehicle routes between the determined locations. As a result, two-stage deployment-routing model made it possible to successfully identify the appropriate delivery model forvaccines to be consumed before the shelf-life period. Scientists in the field of medicine state that such epidemics will be encountered again in the coming years. Therefore, the study will be developed further in the following years and will ensure that the vaccine distribution policy in the country is ready and effective in advance.