This paper discusses a new approach for analyzing queuing models of material control strategies such as kanban, CONWIP and POLCA in manufacturing systems. In practice, these strategies regulate the flow of jobs at various stations of the manufacturing system using a combination of card loops and authorization signals. Queuing models of such systems are composed of closed queuing networks corres...

Multi-supplier inventory systems with seasonal demand are investigated via queuing theory methods in the framework of cost approach. Optimal distribution of replenishment orders between suppliers is obtained under assumption of make-to-order strategy. To this end asymptotic analysis of systems behavior is performed. We apply various mathematical tools such as weak convergence and use properties...

Cellular frequency reuse is known to be an efficient method to allow many wireless telephone subscribers to share the same frequency band. However, for wireless data and multi-media communications optimum cell layouts differ essentially from typical solutions for telephone systems. We argue that wireless radio systems for bursty message traffic preferably use the entire bandwidth in each cell. ...

In part I [1] of this paper, we studied the problem of allocating resources in shared single hub 802.12 networks. We described the packet scheduling model and defined the admission control conditions which enable the network to provide deterministic service guarantees. In this paper, we analyse cascaded (multi-hub) 802.12 topologies. We derive the relevant network parameters and show that the a...

Considering the competition in today’s business environment, tactical planning of a supply chain becomes more complex than before. In many multi-product inventory systems, substitution flexibility can improve profits. This paper aims to prepare a comprehensive substitution inventory model, where an inventory system with two substitute products with ignorable lead time has been considered, and e...

the problem of staff scheduling at a truck hub for loading and stripping of the trucks is an important and difficult problem to optimize the labor efficiency and cost. the trucks enter the hub at different hours a day, in different known time schedules and operating hours. in this paper, we propose a goal programming to maximize the labor efficiency via minimizing the allocation cost. the propo...

Through observations from real life hub networks, we introduce the multimodal hub location and hub network design problem. We approach the hub location problem from a network design perspective. In hub network design problem, we jointly consider transportation costs and travel times, which are studied separately in most hub location problems presented in the literature. We allow different trans...

We introduce the Partitioning-Hub-Location-Routing Problem (PHLRP), a hub location problem involving graph partitioning and routing features. The PHLRP consists of partitioning a given network into sub-networks, locating at least one hub in each sub-network and routing the traffic within the network at minimum cost. This problem finds applications in deployment of an Internet Routing Protocol c...