Designing efficient medical cold supply chain networks: A multi-objective P-hub location and routing model under perishability and capacity constraints

This study proposes an optimization model to strategically locate blood hubs and route blood product flows. The model considers real-world factors, including depreciation costs at hubs, blood wastage, product decomposition at lab centers, and handling of multiple blood products. It employs both single and multiple allocation strategies to mitigate shortages and meet all demand. The proposed multi-objective model aims to: (i) minimize the total cost, such as transportation costs, depreciation costs, and hub installation costs, and (ii) minimize the maximum time that products stay in the network. Computational results show that NSGA-II produces diverse Pareto-efficient solutions and achieves small optimality gaps for small-sized instances when compared with the ε-constraint method, while remaining effective for larger instances where exact methods become computationally intractable. The ε-constraint method is used to derive Pareto optimal solutions, and NSGA-II is applied to solve the proposed model. Sensitivity analysis indicates that blood demand and depreciation costs are the most influential parameters, and that optimal solutions occur at moderate hub capacities. Managerial implications reveal that the optimal number and location of hubs are determined not solely by geography but also by demand distribution, donor availability, and product compatibility.