摘要:

AbstractThis paper describes a research programme which used the idea that there is a‘system of systems methodologies’to analyse the relationship between OR and other systems-based, problem-solving approaches, and to relate different systems methodologies to appropriate problem-contexts. The results are promising for those who wish to broaden the theoretical basis of OR in order to extend its domain of effective application. Further progress, however, depends upon reconstituting the research programme on surer theoretical foundations. Unless this is done, both the potential of the original work and its initial intent risk being lost. It is now necessary to go beyond‘a system of systems methodologies’and to embed that work in an explicit proposal for a critical management science.

ISSN:0160-5682    

DOI:10.1057/jors.1990.96

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThis paper gives a bibliography on applications of multiple-objective methods which use noa prioriexplicit value function and are complex enough to require mathematical programming aids. A commentary on the applications and on the survey is also given which may be helpful for further work of this kind. The survey covers the period 1955-86.

ISSN:0160-5682    

DOI:10.1057/jors.1990.97

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractMuch work has been done on the development of modelling techniques to assist in the process of decision-making. The areas of operational research and statistical analysis are well established, and the speed and memory capacity of computers has facilitated the solution of very large problems using such techniques. Recent developments in artificial intelligence, particularly with regard to expert systems, open up the possibility of modelling the decision-maker rather than the decision situation. This would result in a much more sophisticated decision-support system, but as yet it is an approach which has not been investigated to any significant degree. This paper suggests how AI techniques might be combined with traditional problem-based methodologies to provide a comprehensive decision-analysis support-system framework, modelling the activities of a human decision-maker and providing access to a host of traditional and artificial intelligence tools which can be effectively interfaced.

ISSN:0160-5682    

DOI:10.1057/jors.1990.98

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThis paper reports an application of vehicle-scheduling for the Inner London Education Authority. A semi-interactive, microcomputer-based system was designed and implemented to assist the scheduling of vehicles which deliver meals from kitchens to schools. The scheduling methodology used was heuristic in nature, being based in part on the well-known savings concept and also incorporating a novel approach to the problem of‘time-window’constraints on the collection and delivery of meals.

ISSN:0160-5682    

DOI:10.1057/jors.1990.99

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThe problem of minimizing machine operation cost in a large-scale irrigated double-cropping rice production area in Malaysia was investigated. The combined effects of production environment, climatic conditions and agronomic requirements of the crop require the farmers to rent the machines from cooperatives or from the private sector. However, the high cost of operation and the unique machine demand structure lead to extreme machine shortages. Therefore, a production system which minimizes machine demand is required. In this study, a two-stage cost-minimizing procedure using dynamic programming and linear programming models was studied, and an example is presented.

ISSN:0160-5682    

DOI:10.1057/jors.1990.100

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractVarious models have been used to estimate the amount of oil recoverable from an oil province and the likely sequence of discoveries from any further exploration programme, often with significantly different results. One particular type of model, the discovery-process model, considers oil exploration as a sampling process without replacement, with the underlying size distribution of oilfields determined by the maximum likelihood method. In this paper we consider one example of this type of model, the O'Carroll model, which was previously dismissed as misspecified because of the apparently unrealistic results it gave from early North Sea data. We re-examine this model, solving the integer-constrained maximum likelihood problem in a novel way—as an allocation problem in dynamic programming. Our conclusion is that this model gives a robust estimate of the oil potential in the UK Continental Shelf and a credible distribution of fields yet to be found.

ISSN:0160-5682    

DOI:10.1057/jors.1990.101

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThis paper provides results on the behaviour of the sample autocorrelation function for an ARUMA model—that is, an ARIMA process in which the differencing operator (1−B)dis replaced by a more general real polynomial,Ud(B), having each of its zeros anywhere on the unit circle (subject to the restraint that complex zeros occur in conjugate pairs). Various simulated series are considered, and it is found empirically that the observed sample autocorrelations are in close agreement with appropriate ratios of limiting serial covariance expectations. This agreement is better than that with the theoretical autocorrelations, in the nearly non-stationary case, or the limits of the theoretical autocorrelations (as the homogeneous non-stationarity boundary is approached), in the non-stationary case. We also note some striking features and distinctions in the serial correlation behaviour of processes, according to the position of the zero (or zeros) ofUdon the unit circle, and demonstrate the generally considerable difference between the serial correlations of a non-stationary ARUMA model and a nearly non-stationary approximation to it, obtained by replacing theUd(B) withUd(αB), whereαis a little (but appreciable bit) less than unity.

ISSN:0160-5682    

DOI:10.1057/jors.1990.102

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThe R&D manager is commonly faced with the problem of deciding which projects to fund to meet overall corporate and technical goals. Because outcomes can rarely be predicted with certainty, decisions aimed at striking a balance between cost and risk are likely to involve some amount of redundancy at the project level. The intent of this paper is to examine the difficulties that arise when trying to pursue a parallel strategy in the presence of multiple objectives. The basic elements of the problem include a set of projects, a set of objectives, the associated probability measures relating effort to success, budgetary and performance constraints, and a utility function defined on the range of outcomes. In the model it will be assumed that each project contributes to one or more objectives, and that the selection criterion is based on expected utility maximization. With this in mind, the problem is formulated as a probabilistic goal programme and solved with a heuristic that computes theKbest funding schemes. Results are presented for a case involving the development of a non-petroleum-powered vehicle which demonstrate the robustness of the algorithm and the implications of the underlying decision rules.

ISSN:0160-5682    

DOI:10.1057/jors.1990.103

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractIn this paper we deal with ann-job, single-machine scheduling problem. All jobs are available from the start, and the objective is to minimize the variance of job flow-times. A heuristic procedure which is based on the complementary pair-exchange principle is proposed. It has been concluded that this heuristic procedure provides improved results (in terms of objective-function value) when compared with other heuristics. Our heuristic procedure has the complexity ofO(nlogn).

ISSN:0160-5682    

DOI:10.1057/jors.1990.104

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1990.105

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor