An integrated production and inventory model for a whole green manufacturing supply chain with limited contract period and capacity constraints for suppliers

This paper proposes an integrated production and inventory model for a whole green manufacturing supply chain consisting of multiple-raw materials suppliers, multiple-parts suppliers, a manufacturer, multiple distributors, multiple retailers and a third party collector for used finished products. In the system under study, we consider limited contract period among the players in a specific time period. The number of replenishment cycles has exactly to meet the length of contract period for suppliers in the supply chain. This model also considers capacity constraints of the players and deliveries. The demand quantity is no more than production capacity and minimally meets the minimum demand quantity for each supplier. On the other hand, the order quantity per cycle time has to meet the capacity of delivery units. A model has been formulated for an integrated whole manufacturing supply chain to jointly determine the optimal order quantity and number of unit transportations per cycle across all players in the supply chain in the specific time period of supply chain contract and delivery schedule. Selection of suppliers is also included in solving the model. An optimal solution can be obtained by using mixed-integer nonlinear programming technique. A numerical example is presented and results discussed.