In this work, we consider a continuous-time inventory system where the demand process follows an inventory-dependent diffusion process. The ordering cost of each order depends on quantity and is given by general function, which not even necessarily continuous monotone. By applying lower bound approach together with comparison theorem, show global optimality (s,S) policy for ergodic control prob...

We develop a DSGE model to explain salient empirical regularities regarding fluctuations in aggregate inventory accumulation over the business cycle while simultaneously explaining a distinct set of observations on the behavior of this series at higher frequencies. We begin with a generalized (S,s) model of inventory investment wherein firms fixed costs of ordering inputs that lead them to econ...

F many companies, inventory record inaccuracy is a major obstacle to achieving operational excellence. In this paper, we consider an inventory system in which inventory records are inaccurate. The manager makes inventory inspection and replenishment decisions at the beginning of each period. There is a cost associated with each inspection. If an inspection is performed, inventory records are al...

the traditional economic production quantity (epq) model assumes that during the production process no imperfect item is produced. but in the real production system, due to imperfect production process or other factors, imperfect quality items may be produced. furthermore, it is well-known that the total production-inventory costs can be reduced by reworking the imperfect quality items produced...

An important aspect of retail outlets which offer different kinds of fresh meat is the careful planning of inventory. In this context, inventory management includes ensuring the required quantity of meat, storing it in an adequate way, and also minimizing the setup cost, holding cost, shortage cost and possible losses that might occur if the goods remain unsold. By devising and applying appropr...

Variability, in general, has a deteriorating effect on the performance of stochastic inventory systems. In particular, previous results indicate that demand variability causes a performance degradation in terms of inventory related costs when production capacity is unlimited. In order to investigate the effects of demand variability in capacitated production settings, we analyse a make-to-stock...

We present a problem on risk pooling and cost allocation in inventory of spare parts motivated in the oil and gas sector. Spare parts are held to facilitate operational conditions. Multiple inventory plants control their stock per separate. In practice, however, they supply each other when needed. Risk pooling is a source of savings in this situation. Under a centralized inventory solution, the...

In this paper, we study a production-inventory systems with finite production capacity and fixed setup costs. The demand process is modeled as a mixture of a compound Poisson process and a constant demand rate. For the backlog model we establish conditions on the holding and backlogging costs such that the average-cost optimal policy is of (s, S)-type. The method of proof is based on the reduct...

In this paper we study a type of production-inventory system in which the production and demand rates are modulated by a background state process modeled as a finite state Continuous Time Markov Chain (CTMC). When the production rate exceeds the demand rate, the inventory level increases, and when the demand rate exceeds the production rate, it decreases. When the inventory level reaches zero, ...

⎯There have been many studies on two-stage supply models. Because supply chains are increasingly more complicated, this study considers the three-stage supply chain configurations which involve multiple companies at each stage and each company at the upstream stages can supply two or more customers. The coordination mechanisms for the members along the chain are achieved in the following two as...