摘要:

AbstractThe object of this article is to investigate the risk‐pooling effect of depot stock in two‐echelon distribution system in which the depot servesnretailers in parallel, and to develop computationally tractable optimization procedures for such systems. The depot manager has complete information about stock levels and there are two opportunities to allocate stock to the retailers within each order cycle. We identify first‐ and second‐order aspects to the risk‐pooling effect. In particular, the second‐order effect is the property that the minimum stock available to any retailer after the second allocation converges in probability to a constant as the number of retailers in the system increases, assuming independence of the demands. This property is exploited in the development of efficient procedures to determine near‐optimal values of the poli

ISSN:0894-069X    

DOI:10.1002/1520-6750(198902)36:1<1::AID-NAV3220360102>3.0.CO;2-S

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThis article considers the efficient scheduling of a fleet of ships engaged in pickup and delivery of bulk cargoes. Our optimization system begins by generating a menu of candidate schedules for each ship. This menu can contain all feasible solutions, which guarantees we will find an optimal solution or can be heuristically limited to contain only those schedules likely to be in an optimal solution. The problem of choosing from this menu an optimal schedule for the fleet is formulated as a set‐packing problem and solved with a dual algorithm. Computational experience is presented based on real data obtained from the Military Sealift Command of the U. S. Navy. Run times for this data were reasonable and solutions were generated with the potential of saving up to about $30 million per year over the manual system currently in place. We also describe a color‐graphics interface developed to facilitate interaction with the optimization sys

ISSN:0894-069X    

DOI:10.1002/1520-6750(198902)36:1<27::AID-NAV3220360103>3.0.CO;2-0

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThis article investigates the problem of planning an optimal layered search for a stationary target. A search is layered if it assigns each point in the search space an integer number of glimpses or looks. General necessary and sufficient conditions and an existence theorem are obtained. The special case in which the initial target distribution is bivariate normal is considered in detail.

ISSN:0894-069X    

DOI:10.1002/1520-6750(198902)36:1<43::AID-NAV3220360104>3.0.CO;2-W

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThis article presents a general multiperiod model of an assemble‐to‐order system with component commonality and proves that its solution is myopic. The model is then endowed with a capacity or storage constraint, and the resulting behavior of optimal policies is investigated. Interestingly, with such constraint, the optimal stocks of product‐specific components can be lower in an assemble‐to‐order system than in a corresponding make‐to‐stock one, a behavior that is impossible in an uncons

ISSN:0894-069X    

DOI:10.1002/1520-6750(198902)36:1<61::AID-NAV3220360105>3.0.CO;2-P

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractIn this article we consider a cost‐minimization model to investigate scheduling strategies for multistaged projects in a client‐contractor environment. This type of environment is symptomatic of temporal changes in project definition and scope. At prespecified epochs the client conducts an external evaluation of the project and either accepts or rejects the contractor's current work. The resulting uncertainty from the client's review is modeled via monotonically varying acceptance probabilities. The model is designed primarily to address the interaction between earliest‐, intermediate‐, and latest‐start options and project‐crashing stragies for a broad range of penalty costs. Theoretical results are introduced, while numerical examples for both exponentially and polynomially based acceptance probabilities ar

ISSN:0894-069X    

DOI:10.1002/1520-6750(198902)36:1<69::AID-NAV3220360106>3.0.CO;2-E

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractUntil only recently, the mechanism behind determining item price has been ignored and the discount price taken as a given in quantity‐discount inventory decision problems. Inventory subject to declining demand further complicates both pricing and replenishment decisions. This article provides the vendor with the means for optimally determining both the discount price and replenishment order frequency for all buyers in the system in an environment of declining demand. In the multiple‐buyer case, we provide an efficient algorithm for classifying buyers into homogeneous subgroups to further enhance joint cost savings among all system participa

ISSN:0894-069X    

DOI:10.1002/1520-6750(198902)36:1<89::AID-NAV3220360107>3.0.CO;2-5

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractVarious partial orderings of life distributions have been studied in a unified way with the help of some functions. Two new partial orderings have been defined. Relevance of these partial orderings, for comparing life of a new unit with residual life of a used unit, is discussed.

ISSN:0894-069X    

DOI:10.1002/1520-6750(198902)36:1<103::AID-NAV3220360108>3.0.CO;2-7

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThis article deals with theM/G/1 queue with server vacations in which the return of the server to service depends on the number of customers present in the system. The main goal is optimization, which is done under the average cost criterion in the multiple‐ and single‐vacation models as well as for the “total cost for one busy cycle” criterion in the multiple‐vacation case. Expressions that characterize the optimal number of customers, below which the server should not start a new service period, are exhibited for the various cases. It is found that under the average cost criterion, the expression may be universal in the sense that it may hold for a general class of problems including such that arise in production planning and inventory theory (for the particular cost structure d

ISSN:0894-069X    

DOI:10.1002/1520-6750(198902)36:1<111::AID-NAV3220360109>3.0.CO;2-3

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

ISSN:0894-069X    

DOI:10.1002/1520-6750(198902)36:1<::AID-NAV3220360101>3.0.CO;2-J

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY