摘要:

AbstractThis article concerns a multi‐item, infinite‐horizon, lot‐sizing problem, where the objective is to minimize a total cost function made up of reordering cost, holding cost, and a cost determined by peak inventory levels. By spreading inventory replenishments over the reordering cycle, the peak inventory level can be reduced. The model permits the derivation of simultaneously optimal solutions for the length of the cycle and the individual item replenishment times within the cycle. An alternative formulation, in which total storage capacity is modeled as a constraint, is also s

ISSN:0894-069X    

DOI:10.1002/1520-6750(198806)35:3<319::AID-NAV3220350302>3.0.CO;2-1

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

年代:1988

数据来源: WILEY

摘要:

AbstractThis article provides a Bayes approach for the quality control of a production process which is defined by anM/G/1 queue. An inspection procedure which is jointly optimal from the queue's operational characteristics and quality‐control perspectives is found using a queue‐inspection renewal cycle analysis (with overall expected profit per unit time as the optimization objective). Numerical results are obtained, highlighting the relationships between quality control and (queue‐like) production manag

ISSN:0894-069X    

DOI:10.1002/1520-6750(198806)35:3<327::AID-NAV3220350303>3.0.CO;2-Y

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

年代:1988

数据来源: WILEY

摘要:

AbstractWe present an exact solution method for a single‐server queueing system which alternates between periods in which service can be provided (on‐periods) and periods in which the server is out of operation (off‐periods). The arrival process is Poisson, on‐periods are assumed to have a phase‐type distribution, and service times and off‐periods are assumed to b

ISSN:0894-069X    

DOI:10.1002/1520-6750(198806)35:3<345::AID-NAV3220350304>3.0.CO;2-R

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

年代:1988

数据来源: WILEY

摘要:

AbstractThe orienteering problem involves the selection of a path between an origin and a destination which maximizes total score subject to a time restriction. In previous work we presented an effective heuristic for this NP‐hard problem that outperformed other heuristics from the literature. In this article we describe and test a significantly improved procedure. The new procedure is based on four concepts—center of gravity, randomness, subgravity, and learning. These concepts combine to yield a procedure which is much fasterandwhich results in more nearly optimal solutions than previous procedu

ISSN:0894-069X    

DOI:10.1002/1520-6750(198806)35:3<359::AID-NAV3220350305>3.0.CO;2-H

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

年代:1988

数据来源: WILEY

摘要:

AbstractWhat has been causing cost overruns and schedule slippages in Army major weapon‐system R&D programs during the past ten years? This article addresses this question with emphasis on the effectiveness of an Army acquisition strategy entitled Total Risk Assessing Cost Estimating (TRACE). An empirical study employed a questionnaire and interviews with key personnel from all of the major Army Program Management Offices involved with R&D.The major research question was the following: What explanatory variables have been affecting R&D cost overruns and development time? This includes an evaluation of TRACE as a potential explanatory variable. Data was collected and analyzed using an error components multiple regression model. The major explanatory variables that appeared to explain cost overruns were technological risk of the program, education and experience of key program management office personnel, and the degree of “buy in” by the prime contractor. Strong statistical results indicate that TRACE is having little or no effect on cost overruns. In the case of development time, the major explanatory variables were seen to be technological risk of the program, testing, TRACE, education, and length of the R&D con

ISSN:0894-069X    

DOI:10.1002/1520-6750(198806)35:3<367::AID-NAV3220350306>3.0.CO;2-D

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

年代:1988

数据来源: WILEY

摘要:

AbstractA production process which exhibits a decreasing pattern in the mean quality during the course of production is considered. A lower limit is specified for the quality characteristic of interest, and an item is classified as defective if its quality characteristic is below this lower limit. The major concern of the manufacturer is the average outgoing quality (AOQ). Hence, the process has to be adjusted after a time to avoid producing a large proportion of defective items due to deteriorating quality. To meet consumer specifications, an average outgoing quality limit (AOQL) is specified. A process‐control scheme is developed in which decisions as to the upper and lower limit of the process mean are made based upon the choice of an AOQL. We discuss the decision problem of selecting the starting level of the process mean, and the level at which the process mean should be adjusted back to the starting level, so that the AOQ is not larger than AOQL. We consider a cost model which includes a fixed cost for adjustment, and a production cost which is assumed to be a function of the quality level. Due to the complexity of the model, a search procedure is used to find the optimal solution. In addition, an approximate solution which requires only simple calculations is developed, and is shown to be very effective in finding near‐optimal soluti

ISSN:0894-069X    

DOI:10.1002/1520-6750(198806)35:3<383::AID-NAV3220350307>3.0.CO;2-8

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

年代:1988

数据来源: WILEY

摘要:

AbstractThis article uses game theoretic concepts to analyze the inventory problem with two substitutable products having random demands. It is assumed that the two decision makers (players) who make ordering decisions know the substitution rates and the demand densities for both products. Since each player's decision affects the other's single‐period expected profit, game theory is used to find the order quantities when the players use a Nash strategy (i.e., they act rationally). We prove the existence and uniqueness of the Nash solution. It is also shown that when one of the players acts irrationally for the sole purpose of inflicting maximum damage on the other, the maximin strategy for the latter reduces to using the solution for the classical single‐period inventory problem. We also discuss the cooperative game and prove that the players always gain if they cooperate and maximize a joint objective funct

ISSN:0894-069X    

DOI:10.1002/1520-6750(198806)35:3<397::AID-NAV3220350308>3.0.CO;2-Z

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

年代:1988

数据来源: WILEY

摘要:

AbstractFor more than a decade, multiattribute utility/value theory and multiobjective mathematical programming have offered different approaches to similar problems. Unfortunately, the two areas have developed with little interaction in spite of their common aims. We consider the use of utility/value functions in a mathematical programming framework, and demonstrate that these functions often possess desirable properties from an optimization point of view. We conclude that a hybridization of approaches is more viable than is perhaps commonly assumed.

ISSN:0894-069X    

DOI:10.1002/1520-6750(198806)35:3<411::AID-NAV3220350309>3.0.CO;2-O

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

年代:1988

数据来源: WILEY

摘要:

AbstractThe problem considered in this article is a generalization of the familiar makespan problem, in whichnjobs are allocated amongmparallel processors, so as to minimize the maximum time (or cost) on any processor. Our problem is more general, in that we allow the processors to have (a) different initial costs, (b) different utilization levels before new costs are incurred, and (c) different rates of cost increase. A heuristic adapted from the bin‐packing problem is shown to provide solutions which are close to optimal as the number of iterations is allowed to increase. Computational testing, over a large number of randomly generated problem instances, suggests that heuristic errors are, on average, very smal

ISSN:0894-069X    

DOI:10.1002/1520-6750(198806)35:3<419::AID-NAV3220350310>3.0.CO;2-5

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

年代:1988

数据来源: WILEY

摘要:

AbstractSoftware metrics try to identify, define, and assign various indices of merit that can support the quantitative comparisons and evaluations of software in all phases of its life cycle. This article is a state‐of‐the‐art and state‐of‐the‐practice review of literature related to software quality measurements

ISSN:0894-069X    

DOI:10.1002/1520-6750(198806)35:3<425::AID-NAV3220350311>3.0.CO;2-3

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

年代:1988

数据来源: WILEY