It has been conjectured that MWS-α scheduling policies with α going to zero are heavy-traffic optimal for scheduling in a generalized switch when the objective is to minimize the number of backlogged packets in the system. We examine this conjecture by first deriving optimal or heavy-traffic optimal policies for small switches and then comparing them to MWS-α policies. Our conclusion is that th...

Markov-modulated processes have been used in stochastic inventory models with setup costs for modeling demand under the innuence of uncertain environmental factors, such as uctuating economic and market conditions. The analyses of these models have been carried out in the literature only under the assumption that unsatissed demand is fully backlogged. The lost sales situation occurs in many ret...

We address a multi-item capacitated lot-sizing problem with setup times, stock and demand shortages. Demand cannot be backlogged, but can be totally or partially lost. Safety stock is an objective to reach rather than an industrial constraint to respect. In this paper we consider an approach based on a lagrangean relaxation of the capacity constraints to generate a lower bound of the optimal va...

We address a multi-item capacitated lot-sizing problem with setup times, safety stock and demand shortages. Demand cannot be backlogged, but can be totally or partially lost. Safety stock is an objective to reach rather than an industrial constraint to respect. The problem is np-hard. We propose a Lagrangian relaxation of the resource capacity constraints. We develop a dynamic programming algor...

An order level inventory model for seasonable/fashionable products subject to a period of increasing demand followed by a period of level demand and then by a period of decreasing demand rate three branches ramp type demand rate is considered. The unsatisfied demand is partially backlogged with a time dependent backlogging rate. In addition, the product deteriorates with a time dependent, namel...

In this paper, a multi-product economic production quantity problem with limited warehouse-space is considered in which the orders are delivered discretely in the form of multiple pallets and the shortages are completely backlogged. We show that the model of the problem is a constrained non-linear integer program and propose a genetic algorithm to solve it. Moreover, design of experiments is em...

Abstract A model for inventory systems with multiple products is studied. Demands of items are time-dependent and follow power patterns. Shortages allowed fully backlogged. For this system, our findings provide the efficient policy that helps decision-makers to obtain initial levels reorder points maximize profit per unit time. Moreover, when it assumed warehouse used storage has a limited capa...

This research paper deals with an inventory replenishment model for both deteriorating and ameliorating items under linear trend in demand over a fixed time horizon. aimed to develop the shortages which are partially backlogged. The is developed fuzzy environment. Optimal technique used solve considering Signed Distance Method (SD). ordering cost, purchase holding shortage cost opportunity all ...

Dong-Yong Kwak et al. 475 In this paper, we propose an efficient and simple fair queuing algorithm, called new starting potential fair queuing (NSPFQ), which has O(1) complexity for virtual time computation and also has good delay and fairness properties. NSPFQ introduces a simpler virtual time recalibration method as it follows a rate-proportional property. The NSPFQ algorithm recalibrates the...

Abstract -In this paper, we developed a fuzzy optimal replenishment policy for Inventory models of Weibull Deterioration items with Ramp type Demand under permissible delay in payments. Deterioration of items begins on their arrival in stock. The shortages are allowed and partially backlogged. All the inventory costs involved in this model are taken as triangular fuzzy numbers. Replenishment cy...