We consider the following two deterministic inventory optimization problems over a finite planning horizon T with non-stationary demands. • Submodular Joint Replenishment Problem. This involves multiple item types and a single retailer who faces demands. In each time step, any subset of item-types can be ordered incurring a joint ordering cost which is submodular. Moreover, items can be held in...

This paper analysis single-period inventory models with discrete demand under fuzzy environment. In the proposed models three different cases are examined. In the first case, demand is represented by a triangular fuzzy number and a discrete membership function. In the second case, demand is a stochastic variable while inventory costs such as unit holding cost and unit shortage cost are imprecis...

This paper examines the interactions between routing and inventory-management decisions in a two-level supply chain consisting of a cross-docking warehouse and N retailers. Retailer demand is stochastic; i.e., normally distributed and independent across retailers and over time. Travel times are fixed between pairs of system sites. Every m time periods, system inventory is replenished at the war...

Production Planning (PP) aims at making production decisions optimizing the Manufacturing and Supply Chain performances. Given a limited amount of manufacturing resources, raw materials, and inventory space, PP minimizes the overall manufacturing and supply chain costs while meeting service level requirements and obeying operational constraints. In this research we focus on the sequencedependen...

This paper presents an optimal control recycling production inventory system in fuzzy environment. The used items are bought back and then either put on recycling or disposal. Recycled products can be used for the new products which are sold again. Here, the rate of production, recycling and disposal are assumed to be function of time and considered as control variables. The demand inversely de...

Inventory management requires optimal determination of (a) “when to order”, and (b) “how much to order”. One also needs here two answers—what should be stocked initially, and should one adjust (a) and (b) as time progresses? This paper uses the Bayesian approach to answer these. It uses the classical (s, Q) model and a heuristic search in the unstructured decision space. It finds that one can m...

We consider periodic review inventory control problems in directed networks, primary examples of which are distribution systems and assembly systems. External demand could occur at each node. When inventory is insufficient to meet requirements at a node, a portion of this demand is backordered and the remaining is lost. External demands, as well as lead times for inventory purchase, assembly, a...

This paper investigates the effect of using an end-of-period accounting scheme for inventory related costs when costs actually accrue in continuous time. Using a simple model, we show that (i) the end-of-period scheme results in higher than optimal order-up-to levels and inventory cost if the cost and demand parameters are unchanged, and (ii) it is possible to replicate both the optimal base st...

We consider the periodic review inventory control problem in which the purchasing cost of the product changes, in a Markovian fashion, from one period to the next. After establishing (with and without the non-speculation assumption) that an order upto policy is optimal, we develop an efficient recursive solution procedure to compute the optimal levels. In addition, we propose a measure for the ...