Multiobjective Sourcing and Lot Sizing of Drug with Considering Multi-Sourcing and Lateral Transshipment in Stochastic Conditions with Simulation Optimization Method

In this paper, the issue of integrated supplier selection and inventory policy for a drug distribution company with multiple warehouses is examined. In this research, warehouses are faced with stochastic demand and inventory of their medicines is provided by one or more suppliers that are located in a given set of candidates with price, quality and characteristics of the disruption. In addition, warehouses may be able to supply their holdings from other stores due to the importance of the availability of drugs, in the absence of drugs. With this description, the subject of this research is an integrated multi sourcing and lot sizing, with the consideration of the lateral transshipment between warehouses. The benefits of multi-sourcing and the lateral transshipment between warehouses have been described in reducing the risk associated with potential demand and supply disruptions in the research literature, which has so far not been studied with little consideration in the discussion of the drug. In this research, a Sim-NSGA-II simulation optimization algorithm is presented to solve the problem, and the effect of various disruptions, lateral transshipment and multi-sourcing on the system has been investigated.