Browsing by Subject "Stochastic joint replenishment problem"

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Open Access
A joint replenishment policy with individual control and constant size orders
(Taylor & Francis, 2010) Tanrikulu, M. M.; Şen, A.; Alp, O.
We consider inventory systems with multiple items under stochastic demand and jointly incurred order setup costs. The problem is to determine the replenishment policy that minimises the total expected ordering, inventory holding, and backordering costs-the so-called stochastic joint replenishment problem. In particular, we study the settings in which order setup costs reflect the transportation costs and have a step-wise cost structure, each step corresponding to an additional transportation vehicle. For this setting, we propose a new policy that we call the (s, Q) policy, under which a replenishment order of constant size Q is triggered whenever the inventory position of one of the items drops to its reorder point s. The replenishment order is allocated to multiple items so that the inventory positions are equalised as much as possible. The policy is designed for settings in which backorder and setup costs are high, as it allows the items to independently trigger replenishment orders and fully exploits the economies of scale by consistently ordering the same quantity. A numerical study is conducted to show that the proposed (s, Q) policy outperforms the well-known (Q, S) policy when backorder costs are high and lead times are small.
Open Access
Stochastic joint replenishment problem : a new policy and analysis for single location and two eclehon inventory systems
(2005) Yüksel Özkaya, Banu
In this study we examine replenishment coordination strategies for multiple item or multiple location inventory systems In particular we propose a new parsimonious control policy for the stochastic joint replenishment problem We rst study the single location setting with multiple items under this policy An extensive numerical study indicates that the proposed policy achieves signi cant cost improvements in comparison with the existing policies The single location model also represents a two echelon supply chain for a single item with multiple locations where the upper echelon employs cross docking We then extend our model to incorporate multi location settings where the upper echelon also holds inventory Our modeling methodology based on the development of the ordering process by the lower echelon provides an analytical tool to investigate various joint replenishment policies An extensive numerical study is conducted to determine the performance of the system and identify regions of dominance across policies Keywords S