A location-inventory problem considering restrictions on storing different perishable products with uncertain demands and lead times

This paper studies a location-inventory problem with uncertain demands and lead times in a three-level supply chain including a producer, multiple distribution centres (DCs) and multiple retailers. A number of perishable products such as food and medicine goods are considered with a specific shelf life; unlike the previous studies in the literature, the restrictions of storing different perishable products in identical DC is considered. The objective is to determine the number and location of DCs, the allocation of retailers to DCs, the reorder point and demand rate at each DC. Due to the uncertainty on demands and lead times, a queuing approach is utilized to model the problem. The problem is formulated as an integer nonlinear programming and solved using the Genetic and the Imperialist Competitive algorithms.