A bilevel hierarchical covering model to protect a healthcare network against failures

Official URL: https://dx.doi.org/10.1007/s12351-024-00870-5

This paper develops a bilevel problem to address the interdiction and fortification of the healthcare network in Golestan province, Iran. We explore a bilevel hierarchical covering interdiction/fortification problem (BHCIFP) to analyze the dynamics between interdiction and fortification operations, referral systems for healthcare services, capacitated health facilities, and budgetary constraints for both defense and offense. The defender (leader) aims to minimize the establishment cost of protective equipment and subsequent healthcare costs post-interdiction while maximizing patient coverage. Conversely, the attacker (follower) aims to disrupt the healthcare network by interdicting facilities, thereby increasing the total travel distance for patients. To solve this NP-hard problem, we employ a hybrid approach that integrates the tabu search algorithm (TS) for the leader’s problem with an exact method for the follower’s problem. A case study of Golestan’s healthcare network is presented to validate the model and hybrid approach. The model effectively minimizes travel distances by strategically locating defense bases, considering both the leader’s and attacker’s decisions. Comparative evaluations of the proposed hybrid TS and two other metaheuristic approaches are conducted on different case study instances and random instances. Numerical results demonstrate that the novel bilevel TS approach provides superior quality solutions in a reasonable time, establishing it as a competitive method for the proposed model.