Bi-objective mathematical modelling for a location-relocation problem of hierarchical healthcare facilities under uncertainty and disaster

Since the expansion of urban areas, demographic changes and the existing facilities have gradually been established over the past years, there is a need for them to take a re-examination and it improve in the structure of the networks if needed. This study aims to investigate the recent facilities by building a model for locating and relocating hospital facilities in a hierarchical approach. Additionally, there are some solutions for closing, changing the capacity and opening new facilities if it needs to change in the current structure of facilities. The purposes of this study consist of maximizing the demand coverage and minimizing the structure cost. This model considers the probability occurrence of disturbances and crises, such as the lack of the availability and easy access. On the other hand, coverage radius and the capacity of each hospital facility are affected on the quality and speed of responses so that this study attempts to examine the capacity levels related to facilities and their coverage radius.This means how long any facility can cover the maximum distance of the access point. It is used of the Epsilonconstraintmethod in order to solve the proposed bi-objective model. As a result, this model is implemented asa case study in Qom Hospital facilities and it is shown that the amount of the demand coverage is increased in anacceptable level.