-
作者：Gurler, U; Parlar, M
作者单位：Ihsan Dogramaci Bilkent University; McMaster University
摘要：This paper considers a stochastic inventory model in which supply availability is subject to random fluctuations that may arise due to machine breakdowns, strikes, embargoes, etc. It is assumed that the inventory manager deals with two suppliers who may be either individually ON (available) or OFF (unavailable). Each supplier's availability is modeled as a semi-Markov (alternating renewal) process. We assume that the durations of the ON periods for the two suppliers are distributed as Erlang r...
-
作者：Perez, AP; Zipkin, P
作者单位：Columbia University; Duke University
摘要：This paper develops a simple but effective heuristic policy for a stochastic production-inventory system, where several products share a single processor of limited capacity. Our policy combines the best features, and avoids the weaknesses, of prior approaches in the literature. Limited numerical tests suggest that the method performs well.
-
作者：Sethi, SP; Cheng, F
作者单位：University of Texas System; University of Texas Dallas; International Business Machines (IBM); IBM USA
摘要：This paper is concerned with a generalization of classical inventory models (with fixed ordering costs) that exhibit (s, S) policies. In our model, the distribution of demands in successive periods is dependent on a Markov chain. The model includes the case of cyclic or seasonal demand. The model is further extended to incorporate some other realistic features such as no ordering periods and storage and service level constraints. Both finite and infinite horizon nonstationary problems are cons...
-
作者：Sun, DN; Atkins, D
作者单位：University of British Columbia
摘要：In the previous work, we have shown that for a production/inventory system arranged in series with backlogging at its final product, the total cost of the best power-of-two frequency lot-size heuristic is within 6% of the optimal (or 2% if the base period is allowed to vary). In this paper, we extend our results to an assembly production/inventory system with constant external demand at its final product with backlogging allowed. By using a submodular property, we show that the total cost of a...
-
作者：Crama, Y; Van de Klundert, J
作者单位：University of Liege; Maastricht University
摘要：We consider a robotic flowshop in which one type of product is to be repeatedly produced, and where transportation of the parts between the machines is performed by a robot. The identical parts cyclic scheduling problem is then to find a shortest cyclic schedule for the robot; i.e., a sequence of robot moves that can be infinitely repeated and that has minimum cycle time. This problem has been solved by Sethi et al. (1992) when m less than or equal to 3. In this paper, we generalize their resu...
-
作者：Hassin, R; Haviv, M
作者单位：Tel Aviv University; Hebrew University of Jerusalem
摘要：Multiplicity of solutions is typical for systems where the individual's tendency to act in a certain way increases when more of the other individuals in the population act in this way. We provide a detailed analysis of a queueing model in which two priority levels can be purchased. In particular, we compute all of the Nash equilibrium strategies (pure and mixed) of the threshold type.
-
作者：Nahmias, S; Moinzadeh, K
作者单位：Santa Clara University; University of Washington; University of Washington Seattle
摘要：We consider a single inventory item that is graded into one of two quality levels after production. The proportion of grade one units produced in a lot is a random variable assumed to follow the lognormal distribution. Demands for grade 2 may be filled with grade I product, but not vice versa. Assuming that demands for the two grades are known and constant, we develop a continuous review model in which cycles are defined as times when total inventory equals zero. Since grade 1 inventory may be...
-
作者：Day, PR; Ryan, DM
摘要：The construction of flight attendant (cabin crew) rosters for short-haul (domestic) airline flight services that satisfies rostering constraints and employment contract regulations is a combinatorially complex problem. In this paper the problem is described and an effective optimisation-based solution method is introduced. The rostering problem involves the allocation of days-off and various duties to each crew member over a roster period. The days-off and the duty allocation problems are sepa...
-
作者：Griggs, BJ; Parnell, GS; Lehmkuhl, LJ
作者单位：Virginia Commonwealth University; United States Department of Defense; United States Air Force; US Air Force Research Laboratory
摘要：This paper describes the development of an air mission planning algorithm for the Joint Stochastic Warfare Analysis Research (JSTOCHWAR). The overall problem scope was to develop an algorithm to handle major factors bearing on the combat mission planning problem while providing hook-ups for the JSTOCHWAR architecture. Other aspects of the problem included finding the appropriate level of detail, developing a fast solving technique, and attempting to use existing data. The problem was handled b...
-
作者：Gans, N; VanRyzin, G
作者单位：Columbia University
摘要：We consider a general class of queueing systems with multiple job types and a flexible service facility. The arrival limes and sizes of incoming jobs are random, and correlations among the sizes of arriving job types are allowed. By choosing among a finite set of configurations, the facility can dynamically control the rates at which it serves the various job types. We define system work at any given time as the minimum time required to process all jobs currently in the backlog. This quantity ...
