Due to environmental protection and limited resource utilization at optimum level, remanufacturing of defective products or reused products is an essential strategy in green supply chain inventory control system. This paper presents a green supply chain inventory model for integrated production of new items and remanufacturing of redeemable returned items under a situation in which the vendor provides the buyer with a permissible delay of payments and supplies the serviceable items to the buyer on lot-for-lot basis. It is assumed that every member of the chain is ready to collaborate for the maximum benefit of the supply chain. A mathematical formulation is developed to derive the optimal number of deliveries and the replenishment cycle time for the integrated vendor-buyer inventory model. Theoretical results show the global optimality of the solution and it is concluded that the collaboration is profitable for the chain and participating members reach the optimal level under co-operative decision making. Numerical analysis is given to illustrate the theoretical results. Finally, a sensitivity analysis is reported to study the effect of various parameters.

Environmental responsibility plays a significant role in the firm’s agendas nowadays. In this paper, we address the environmental operations of reverse logistics. Here we developed an integrated supply chain model with coordinated production and remanufacturing due to time-dependent rates. To study the problem we consider the demand to be satisfied with newly manufactured (produced) and the remanufactured products, so there is no difference between manufactured and remanufactured items. The shortages are allowed and excess demand is backlogged as well. The returned items are collected from the end user to be remanufactured. Optimal expression is obtained for the acceptable returned quantity, maximum inventory level, production and remanufacturing scheduling period, and the total average cost. Illustrative examples, which explain the application of the theoretical results as well as their numerical verifications, are given. The sensitivity of these solutions to change in underling parameter values is also discussed.