classical deterministic inventory models consider the demand rate to be either constant or time-dependent but independent from the stock status. however, for a certain type of inventory, the demand rate may be in-fluenced by the stock level. also in many real-life problems, some products such as fruits, vegetables, phar-maceuticals and volatile liquids continuously deteriorate to evaporation, o...

Remanufacturing is one of the ways forward for product recovery initiatives and maintaining sufficient production flow to satisfy customer demand by providing high-quality goods with a combination new return parts through circular economy. Recently, manufacturers have been progressively incorporating remanufacturing processes, making their supply chains vulnerable disruptions. One main disrupti...

In this paper we study a periodic review single item single stage inventory system with stochastic demand. In each time period the system must order none or at least as much as a minimum order quantity Qmin. Since the optimal structure of an ordering policy with a minimum order quantity is complicated, we propose an easy-to-use policy, which we call (R,S,Qmin) policy. Assuming linear holding an...

Materials are often ordered in batches at fixed time intervals in supply chains. We model such a periodic batch-ordering practice as echelon (r, nQ, T ) policies. In addition to linear holding and backorder costs, we consider two types of fixed costs, setup and order costs. The former is incurred for each batch Q ordered; the latter is associated with each reorder interval T . The objective is ...

An extended economic production quantity (EPQ) model under stochastic demand is investigated in this paper, where a fixed lot sizing policy is implemented to reduce the complexity of production planning and inventory control, and outsourcing with a secondary facility is used to supplement the lot sizing policy and to cope with the random demand. The considered cost includes: setup cost for the ...

The aim of this paper is to introduce a model for temporary staffing when temporary employment is managed by firm contracts and to propose a simulated annealing-based method to solve the model. Temporary employment is a policy frequently used to adjust the working hour capacity to fluctuating demand. Temporary workforce planning models have been unnecessarily simplified to account for only peri...

This paper considers a single-product inventory system that serves both online and traditional customers. Demands from both channels follow independent stationary Poisson processes. Traditional customers have their demands fulfilled upon arrival if the retailer has stock on hand; otherwise the demand is lost. However, online customers place their orders in advance, and delivery is flexible in t...

We investigate a periodic inventory system for a single item with stochastic demand and random yield. Since the optimal policy for such a system is complicated we study the class of stationary linear-inflation policies where orders are only placed if the inventory position is below a critical stock level, and where the order quantity is controlled by a yield inflation factor. We consider two di...