摘要:

AbstractIn this paper we report on a case study involving the location of benefit distribution facilities (benefit posts) in Brazil. Significant improvements in the distribution of benefits are anticipated as a result of this study.

ISSN:0160-5682    

DOI:10.1057/jors.1993.179

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

AbstractThis paper describes the scheduling of the matches for the 1992 World Cup of Cricket using a heuristic method programmed in Lotus 1-2-3. The many constraints of different types precluded an analytical approach and the authors describe their method and solution.

ISSN:0160-5682    

DOI:10.1057/jors.1993.180

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

AbstractA collection of papers on the application of Markov decision processes is surveyed and classified according to the use of real life data, structural results and special computational schemes. Observations are made about various features of the applications.

ISSN:0160-5682    

DOI:10.1057/jors.1993.181

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

AbstractAvailability measures are given for a repairable system under minimal repair with constant repair times. A new policy and an existing replacement policy for this type of system are discussed. Each involves replacement at the first failure after timeT, withTrepresenting total operating time in the existing model and total elapsed time (i.e. operating time + repair time) in the new model. Optimal values ofTare found for both policies over a wide range of parameter values. These results indicate that the new and administratively easier policy produces only marginally smaller optimal availability values than the existing policy.

ISSN:0160-5682    

DOI:10.1057/jors.1993.182

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

AbstractOptimal inspection and replacement policies for a device subject to non-Markovian stochastic failures are derived in the case of inspections that may fail to provide a correct description of the state of the system. Two types of policies are considered, differing in the strategy followed in case of reported failure: one-test policies prescribe replacement, whereas two-test policies prescribe a more accurate work-up, designed to avoid the replacement of a functioning unit. For both cases and arbitrary failure distributions, general optimality conditions and algorithms that reduce the infinite horizon optimization to two dimensions are derived. Properties of the optimal policy, like monotonicity of the times between inspections, are studied. Methods for the implementation of fast computational algorithms are suggested.

ISSN:0160-5682    

DOI:10.1057/jors.1993.183

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

AbstractIn this paper we develop a new approach to monitor the accuracy of an inventory management system. A recorded stock level is considered accurate when the recorded level agrees with the actual stock level, otherwise there is an error. In practice, management relies on methods to measure or assure inventory accuracy not necessarily developed for this purpose. Our methodology is based on the average absolute relative difference as a simple analytical measure for inventory accuracy (ACN). The approach captures the status of accuracy in an inventory and allows for greater understanding of what affects inaccuracy since the theoretical measure of accuracy is composed of several parameters representing the incidence and proportion of both overstock and understock. The implementation of the methodology is constrained because complete inspection of the inventory is very expensive in most situations, so we develop the sample analogue of the accuracy measure (ACn) and discuss sampling strategies. The accuracy of the inventory system is monitored by incorporatingACninto a univariate control chart.

ISSN:0160-5682    

DOI:10.1057/jors.1993.184

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

AbstractThis paper compares regression analysis and data envelopment analysis as two alternative methods for assessing the comparative performance of homogeneous organizational units such as bank branches or schools. The comparison is restricted to units using a single resource or securing a single output. It focuses on the estimates of relative efficiency, marginal input-output values and target input-output levels that the two methods offer. A set of hypothetical hospitals is used to illustrate the performance of the two methods. It is found that, in general, data envelopment analysis outperforms regression analysis on accuracy of estimates but regression analysis offers greater stability of accuracy.

ISSN:0160-5682    

DOI:10.1057/jors.1993.185

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

AbstractThis article presents an extension of a dynamic programming algorithm for scheduling production of multiple items on a single machine with time-varying deterministic demands. The extension handles time-varying deterministic material supply constraints. The algorithm minimizes the sum of changeover and inventory holding costs under two assumptions. First, we assume that in each time period, within the planning horizon, the machine must either be shut down or be producing some one item for the entire time period. Second, we assume that inventory holding costs are the same for all items and are representable as a non-decreasing function.

ISSN:0160-5682    

DOI:10.1057/jors.1993.186

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

AbstractThis study extends the research on international portfolio diversification with estimation risk. The model suggested by Jorion is used to derive the predictive distribution of future returns. The estimator is then compared with the classical one for both with and without short sales. It is found that the improvement for various optimal portfolios is greater for the case of short sales than the case of no short sales.

ISSN:0160-5682    

DOI:10.1057/jors.1993.187

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1993.188

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor