A Sustainable Supply Chain Inventory Model with All-units Quantity Discount and Shipping Weight

In this article, we study an integrated inventory model for a single-seller and a single-buyer by considering the emission and quantity discount. The type of discount policy offered by the seller to the buyer is an all-units quantity discount. The emissions are generated by seller-buyer activities, loading-unloading, and transportation activities. We consider lead-times that depend on the production, transportation, loading-unloading, and in-transit activities. The objective is to minimise the integrated total cost considering all-units quantity discount. We optimize the decision variables, such as: the lot size, number of deliveries, safety stock, lead-time, and carbon emissions. Numerical example is used to illustrate the proposed model.