An optimization framework for emergency supply chains prioritizing elderly populations during pandemics

Pandemics have severely disrupted supply chains, making it challenging to meet the demands of the elderly and other vulnerable populations. This study addresses the importance of developing a sustainable emergency supply chain network that ensures timely and fair resource allocation for elderly communities. Therefore, an age-structured Susceptible-Infected-Recovered (SIR) system dynamics framework is utilized to simulate pandemic development and estimate age-specific demand for highly-demand items. Then, a multi-objective stochastic mathematical model is proposed to optimize cost, decrease unfulfilled demand, and reduce environmental effects. A numerical example inspired by the recent COVID-19 pandemic in Mexico is introduced, which focuses on the distribution of personal protective equipment (PPE), medical supplies, and test kits to hospitals, pharmacies, and other demand points. This approach couples the estimated demand from the system dynamics model and then optimizes the stochastic model. The results present optimal decisions for allocation, inventory, product flow, distribution, and waste management under different scenarios. A sensitivity analysis for the demand parameter is also performed, showing that total cost, unmet demand, and environmental effects increase as demand rises. The study demonstrates the model's capacity to enhance supply chain resilience and adaptability, providing valuable insights to improve emergency responses for at-risk populations.