We present a model of two-echelon retailer inventory systems, and we cast the problem of generating optimal control strategies into the framework of dynamic programming. We formulate two speci c case studies, for which the underlying dynamic programming problems involve thirty-three and forty-six state variables, respectively. Because of the enormity of these state spaces, classical algorithms ...

We study a multi-item, two-echelon, continuous-review inventory problem at a Dutch utility company, Liander. We develop a model that optimizes the quantities of service parts and their allocation in the two-echelon network under an aggregate waiting time restriction. Specific aspects that we address are emergency shipments in case of stockout, and batching for regular replenishment orders at th...

this paper aims to evaluate inventory cost of a two-echelon serial supply chain system under vendor managed inventory program with stochastic demand, and examine the effect of environmental factors on the cost of overall system. for this purpose, we consider a two-echelon serial supply chain with a manufacturer and a retailer. under vendor managed inventory program, the decision on inventory le...

We show the optimality of state dependent echelon base stock policies in uncapacitated serial inventory systems with Markov modulated demand and Markov modulated stochastic leadtimes in the absence of order crossing. Our results cover finite time horizon problems as well as infinite time horizon formulations, with either a discounted or an average cost criterion. We employ a novel approach, bas...

We show the optimality of state-dependent echelon base-stock policies in uncapacitated serial inventory systems with Markov-modulated demand and Markov-modulated stochastic lead times in the absence of order crossing. Our results cover finite-time horizon problems as well as infinite-time horizon formulations, with either a discounted or an average cost criterion. We employ a novel approach, ba...

Customers with positive demand lead times place orders in advance of their needs. A portfolio of customers with different demand lead times gives rise to what we call advance demand information. We develop effective inventory policies for a distribution system to account for this information. In particular, we study a centralized system with one warehouse serving multiple retailers under advanc...

Naval Supply Systems Command recently employed the Navy Enterprise Resource Planning Single Supply Solution to improve efficiency through the sharing of data across the organization. For the first time, replenishment decisions were made using shared enterprise data. Since all items from all sites are in one central database, Weapon Systems Support has total visibility of assets across all avail...

This paper analyses an infinite horizon two-echelon supply chain inventory problem and shows that a sequence of the optimum ordering policies does not yield globally optimal solutions for the overall supply chain. First-order autoregressive demand pattern is assumed and each participant adopts the order-up-to (OUT) policy with a minimum mean square error forecasting scheme to generate replenish...

Many studies focus on inventory systems to analyze different real-world situations. This paper considers a two-echelon supply chain that includes one warehouse and one retailer with stochastic demand and an up-to-level policy. The retailer’s lead time includes the transportation time from the warehouse to the retailer that is unknown to the retailer. On the other hand, the warehouse is unaware ...