This paper demonstrates optimal policies for capacitated serial multiechelon production/inventory systems. Extending the Clark and Scarf (1960) model to include installations with production capacity limits, we demonstrate that a modified echelon base-stock policy is optimal in a two-stage system when there is a smaller capacity at the downstream facility. This is shown by decomposing the dynam...

This paper investigates the impacts inventory shortage policies have on transportation costs in base-stock distribution systems under uncertain demand. The model proposed demonstrates how backlogging arrangements can serve to decrease the variability of transportation capacity requirements, and hence the magnitude of transportation costs, when compared with policies that expedite demand shortag...

In this paper, we establish an exact framework for a class of supply chains with at most one directed path between every two stages. External demands follow compound Poisson processes, the transit times are stochastic, sequential, and exogenous, and each stage controls its inventory by an installation base-stock policy under continuous review. Unsatisfied demand at each stage is fully backorder...

We consider the classic N -stage serial supply systems with linear costs and stationary random demands. There are deterministic transportation leadtimes between stages, and unsatisfied demands are backlogged. The optimal inventory policy for this system is known to be an echelon base-stock policy, which can be computed through minimizing N nested convex functions recursively. To identify the ke...

We consider a production-inventory system with capacity constraint and item returns correlated to demand. The system is modelled by an M/M/1 make-to-stock queue with lost sales. A satisfied demand incurs an item return with a certain probability, after an exponentially distributed return lead-time. We distinguish two cases: When the number of items to be returned is observable and when it is no...

We analyze a multistage inventory system with limited production capacity facing stochastic demands. Each node follows a periodic-review base-stock policy for echelon inventory: in each period, each node attempts to produce enough material to restore cumulative downstream inventory to a fixed target level. We develop approximations to the key measures of interest (average inventories, average b...

We consider the problem of allocating production capacity among multiple items, assuming that a fixed proportion of overall capacity can be dedicated exclusively to the production of each item. Given a capacity allocation, production of each item follows a base-stock policy, i.e., each demand triggers a replenishment order to restore safety stocks to target levels. We present procedures for cho...

Capacity reservation contracts and spot markets are two alternative purchasing practices. We focus on the cost-effective management of the combined use of these two procurement sources. Due to the variability of the spot market prices and demand uncertainty, the flexibility of combined sourcing can be advantageous. Spot market purchasing is a benefit in case of low spot market prices or insuffi...

The purpose of this paper is to develop a general framework for supply contracts in which portfolios of contracts can be analyzed and optimized. We focus on a multi-period environment with convex supply contracts, convex spot market costs and convex inventory holding costs. We characterize the optimal replenishment policy for a portfolio consisting of long-term and option contracts and show tha...