All intensively studied and widely applied inventory control policies satisfy demand in accordance with the First-Come-First-Served (FCFS) rule, whether this demand is in backorder or not. Interestingly, this rule is sub-optimal when the fill-rate is constrained or when the backorder cost structure includes fixed costs per backorder and costs per backorder per unit time. In this paper we study ...

We consider Independent Base-Stock (IBS) policies in Assemble-to-Order (ATO) inventory systems with a general bill of materials and deterministic nonidentical lead times. The main drawback of IBS policies in this setting is that they keep the inventory position of each component constant without considering the availability of other components with longer lead times. We show that the cost of th...

Start-up companies are considered an important factor in the success of a nation’s economy. We are interested in the decisions for long-term survival of these firms when they have considerable cash restrictions. In this paper we analyse several inventory control models to manage inventory purchasing and return policies. The Markov decision models are formulated for both established companies th...

Stochastic dynamic programming models are extensively used for sequential decision making when outcomes are uncertain. These models have been widely applied in different business contexts such as inventory control, capacity expansion, cash management, etc. The objective in these models is to deduce optimal policies based on expected reward criteria. However, in many cases, managers are concerne...

Inventory policies for joint remanufacturing and manufacturing have recently received much attention. Most efforts, though, were related to (optimal) policy structures and numerical optimization, rather than closed form expressions for calculating near optimal policy parameters. The focus of this paper is on the latter. We analyze an inventory system with unit product returns and demands where ...

For general state and action space Markov decision processes, we present sufficient conditions for convergence of both the optimal discounted cost value function and policies to the corresponding objects for the average costs per unit time. We extend Schäl’s [24] assumptions, guaranteeing the existence of a solution to the average cost optimality inequalities for compact action sets, to non-com...

Inventory control is a crucial activity for many companies. Given the recent advances in information technology, there have never been greater opportunities for coordinated inventory control across supply chain facilities. But how do we design efficient control methods and policies that take advantage of the detailed information that is now becoming available? This doctoral thesis investigates ...

now a days, management and control of perishable inventories is important in many units and industrial enterprises. basically perishable inventory management and control is more complex and challenging than inventories with unlimited lifetime. hence determining the optimal inventory policies for these products is very important.  in this paper, the optimal inventory policy for perishable items ...

This paper considers a two-echelon capacitated supply chain with two non-identical retailers and information sharing. We characterize the optimal inventory policies. We also study the benefits of the optimal stock rationing policy over the first come first served (FCFS) and the modified echelon-stock rationing (MESR) policies. © 2006 Elsevier B.V. All rights reserved.

Note. This original form of this rebuttal was submitted to Science on 3 March 2017 (limited to 300 words as per Science editorial policy) but rejected on 13 March 2017. Herein, we elaborate on our original Science submission in order to more fully address the issue without the length limitations. This rebuttal is followed by the list of the signatories who supported our original submission.