Abstract: This paper deals with inventory systems with product return.Products storage covers both remanufactured product and those new ones in general production process,this makes optimal inventory systems extremely complicated.Some EOQ models are derived which determine the optimal production and reproduction lot sizes for different sort of policies.Moreover,a modified method is proposed to ensure discreteness of the number of orders for production or reproduction.With simple form and simple structure,this model is easy to apply in practice.

Key words: logistics system management, returned logistics, inventory control, economic order quantity