We study the continuous-review (r; q) system in which un_lled demands are treated as lost sales. The reorder point r is allowed to be equal to or larger than the order quantity q. Hence, we do not restrict our attention to the well-known case with at most one replenishment order outstanding, but...

Emergency orders have shorter lead times but incur extra costs compared to normal orders. We present a discrete-time Markov decision model where normal orders are issued according to a reorder point policy with a fixed order quantity, whereas emergency orders are controlled by a state-dependent...