We consider a manufacturer facing single period inventory planning problem with uncertain demand and multiple options of expediting. The demand comes at a certain time in the future. The manufacturer may order the product in advance with a relatively low cost. She can order additional amount by expediting after the demand is realized. There are a number of expediting options, each of which corresponds to a certain delivery lead time and a unit procurement price. The unit procurement price is decreasing over delivery lead time. The selling price is also decreasing over time. In this paper, we assume that the manufacturer must deliver all products to the customer in a single shipment. The problem can be formulated as a profit maximization problem. We develop structural properties and show how the optimal solution can be identified efficiently. In addition, we compare our model with the classical newsvendor model and obtain a number of managerial insights. Highlights ► We consider a newsvendor problem with multiple options of expediting. ► We develop a number of structural properties that help to solve the problem efficiently. ► We examine how the demand variation affects the optimal decisions and profits.

Motivated by emerging practice in the cut flower industry, we consider a periodic-review inventory system for a perishable product with a lifetime of two periods. There are two separate customer demands for the new product with two-period remaining lifetime and the old product with one-period remaining lifetime, and a fixed proportion of the unsatisfied demand for one product will purchase the other product as a substitute. One distinctive feature of our system is that a random portion of the sold new product is returned and can be remanufactured and remarketed as the old product for sale. The objective is to maximize the expected total discounted profit over a finite planning horizon. We show that the optimal remanufacturing policy is a modified base–stock policy, and that the optimal manufacturing quantity of the new product decreases in the inventory level of the old product after remanufacturing. Furthermore, when the inventory level of the old product is large, the optimal manufacturing quantity asymptotically approaches a constant, which is lower and upper bounded by two newsvendor fractile solutions. We also conduct a numerical study to derive insights into the effects of remanufacturing and demand substitution. In particular, we show that remanufacturing can be a powerful way of mitigating negative environmental impacts in the cut flower industry. Finally, we discuss two model extensions that allow a joint production capacity and a multi-period lifetime.

We consider a component acquisition problem for a contract manufacturer who faces a one-time stochastic demand for a single product consisting of a number of components. Components can be ordered early at normal prices before the demand is revealed, or they can be replenished later at higher prices due to expediting. In addition, the customer pays a price for the final product that is nonincreasing in the delivery lead time to discourage late delivery. We propose a cost-minimization model and develop an efficient polynomial time algorithm to solve the problem.

This study considers a stochastic inventory management problem where a capital-constrained firm can obtain additional working capital through inventory-based financing (IBF) by pledging its inventory to obtain loans from a lender. We show that the firm's optimal inventory policy in each period may order new inventory up to a state-dependent order-up-to level subject to the firm's capital and IBF loan constraints, or salvage existing inventory down to a state-dependent salvage-down-to level. We further partially characterize the structures of the two state-dependent levels in each period. Through analytical and numerical studies, we offer a number of new insights regarding the optimal inventory management for a capital-constrained firm with access to inventory-based financing. In particular, we find that when the firm anticipates a shortage of capital with which to meet high demands in a future period, it may strategically over-stock its inventory in earlier periods in order to secure the necessary capital. Through extensive numerical studies, our study also demonstrates how some of the key parameters may affect the optimal inventory policy and the value of IBF.

This paper considers an inventory and production-planning problem for a contract manufacturer who anticipates an order of a single product, but with uncertain quantity. To meet the challenges of long component procurement lead times and limited assembly capacity, which may render production time insufficient to assemble total order quantity, the manufacturer may need to procure components or even assemble some quantities of the final product before receiving the confirmation of the actual order quantity. We present profit-maximization models that make optimal inventory and production decisions in the above assemble-to-order environment. We also consider the option of outsourcing, so that the manufacturer can outsource part of his production to an external facility that also has limited capacity. We establish structural properties of optimal solutions and develop efficient solution procedures for the proposed problems. We also provide sensitivity analysis of the optimal decisions, and some managerial insights.