A multi-period and bi-objective approach for locating ambulances: a case study in Belo Horizonte, Brazil

Abstract

This study applies a covering facility location problem in the emergency medical service (EMS) of Belo Horizonte, Brazil. It is proposed a deterministic and a stochastic multi-period model, which allows ambulances to move among bases in different periods to raise the system coverage. The proposed models handle the decisions of base locations and ambulance allocation/relocation. This paper also proposes a bi-objective approach aiming to minimise the number of bases and maximise the coverage of demands, which is solved using the ε-constraint method. Results show that coverage levels increased when scenarios change from static to multi-period. Also, since the multi-period model solutions result in installing a larger number of bases, the bi-objective approach shows to be a powerful tool for the decision-maker to analyse the trade-off between the operational challenges of increasing the number of bases and the increase of coverage.