Abstract:

Emergency medical supplies are important materials to guarantee people's life safety in emergencies. Frequent public emergencies increase the risk of the interruption of the supply chain of emergency medical supplies， seriously impacting people's work and life safety. The immediate reason of supply chain disruption is the explosion of downstream demand for emergency medical supplies caused by public emergencies， and the root cause is the cost-oriented supply chain design of the enterprises， i.e.， reduction in inventory and highly concentrated raw material procurement by only a few enterprises for cost reduction. Therefore， it is imperative to improve the resilience of the supply chain of emergency medical supplies， such as by increasing redundancy and multi-source procurement.In the context of infectious public health emergencies， this paper constructs a three-level supply chain of emergency medical supplies， consisting of suppliers， manufacturers and market demand. The SEIR dynamics model is used to forecast the demand for emergency medical supplies， and resilience is embedded in its supply chain through multi-source procurement and increased redundancy. Meanwhile， considering the impact of the supply chain on social welfare， environmental pollution， resource consumption， government subsidies and other factors are quantified to constitute the total cost of the supply chain. Via mathematical modeling， a dual-objective mixed-integer programming model is constructed to take into account of both resilience and cost. The model minimizes the total expected cost and maximizes the total satisfaction rate of demand， aiming at solving the network design of the supply chain of emergency medical materials supply chain. The dual-objective model is then converted to a single-objective model by the weighted-sum method， and the weight parameter is used to indicate the degree of emphasis on resilience and cost in decision-making. Finally， the validity of the model is verified via simulation， comparative analysis and sensitivity analysis.The results indicate that compared with the cost-oriented supply chain， the supply chain model presented in this paper increases the total demand satisfaction by 16.84% while the expected total cost only increases by 2.10%. It also shows stronger resilience under public health emergencies. Additionally， it is found that the manufacturers should keep the minimum logistics volume with the resilient-oriented auxiliary supplier when maintaining main logistics with the cost-oriented dominant supplier. Significant emergency medical supplies should be kept in the highest inventory to cope with demand fluctuations within a small and medium range. In addition， the supply chain still needs to pay the cost to set up a sufficient reserve capacity to tackle wide demand fluctuations. The model presented in this paper can effectively improve the resilience of the supply chain of emergency medical supplies with while taking cost into account and provide suggestions for the design of a resilient supply chain of emergency medical supplies.

Key words: emergency medical supplies, supply chain modeling, resilience, social welfare