摘要:

AbstractThe modeller approaching discrete-event simulation has expected and received a high degree of computer support. The processing power simply to run a model and analyse the results would, of course, be taken for granted, but support has gone far beyond this in promoting the easier and speedier construction of models through specialized program structures, languages and lately program generators. Computer graphics capabilities of mini- and microcomputers have been exploited to secure a readier acceptance of simulation models and results. These support facilities constitute the computer environment within which the fortunate modeller works at present. What more could be expected?The work of an L.S.E. group of researchers is guided by a picture of an ideal environment for simulation modelling. We shall describe this picture and illustrate the progress made towards its implementation. Our principal intention is to promote discussion amongst simulation practitioners about their own‘ideal’of a computer support environment and the nature of deficiencies in the current systems.

ISSN:0160-5682    

DOI:10.1057/jors.1986.79

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractAn integrated plant design and scheduling problem in the food industry is discussed, and a solution is proposed. This involves the use of two models. The first model is an integer programming model that deals with long-term decisions. The second model deals with decisions that have to be made instantly.

ISSN:0160-5682    

DOI:10.1057/jors.1986.80

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractEarlier work has criticized the dominant tendencies in operational research contributions to health services planning as characterized by optimization, implausible demands for data, depoliticization, hierarchy and inflexibility. This paper describes an effort which avoids at least some of these pitfalls. The project was to construct a planning system for a regional health council in Ontario, Canada, which would take account of the possible alternative future states of the health-care system's environment and would aim to keep options for future development open. The planning system devised is described in the paper. It is based on robustness analysis, which evaluates alternative initial action sets in terms of the useful flexibility they preserve. Other features include the explicit incorporation of pressures for change generated outside the health-care system, and a satisficing approach to the identification of both initial action sets and alternative future configurations of the health-care system. It was found possible to borrow and radically‘re-use’techniques or formulations from the mainstream of O.R. contributions. Thus the‘reference projection’method was used to identify inadequacies in performance which future health-care system configurations must repair. And Delphi analysis, normally a method for generating consensus, was used in conjunction with cluster analysis of responses to generate meaningfully different alternative futures.

ISSN:0160-5682    

DOI:10.1057/jors.1986.81

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractA description is given of work undertaken in conjunction with Lancashire Social Services Department in order to develop a formula to be used as a basis for allocating social workers between social work teams. The basis of the work is a census of elderly and physically handicapped clients. Statistical analyses then lead to categories of clients that have significantly different workload implications. The categories are weighted to reflect their workload implications and their priority in a way that allows the relative needs of social work teams to be estimated.

ISSN:0160-5682    

DOI:10.1057/jors.1986.82

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractIn an integrated crop and intensive beef production enterprise, some of the feedstuffs used for cattle feeding are grown by the enterprise. In evaluating the performance of operations of this type, the interactions between the crop and beef production parts of the enterprise must be taken into account. A linear programming (L.P.) model of this type of enterprise is developed, with the coefficients of the animal feeding activities being derived from a dynamic programming (D.P.) model. This D.P. model is used to determine the least-cost method of feeding animals to produce a specified liveweight gain using rations formulated by L.P. from a given set of feedstuffs. This approach allows the interactions between crop and livestock production to be taken into account without the need to make assumptions about the source of feedstuffs or the rate of liveweight gain.

ISSN:0160-5682    

DOI:10.1057/jors.1986.83

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractFacility location models are applicable to problems in many diverse areas, such as distribution systems and communication networks. In capacitated facility location problems, a number of facilities with given capacities must be chosen from among a set of possible facility locations and then customers assigned to them. We describe a Lagrangian relaxation heuristic algorithm for capacitated problems in which each customer is served by a single facility. By relaxing the capacity constraints, the uncapacitated facility location problem is obtained as a subproblem and solved by the well-known dual ascent algorithm. The Lagrangian relaxations are complemented by anaddheuristic, which is used to obtain an initial feasible solution. Further, a final adjustment heuristic is used to attempt to improve the best solution generated by the relaxations. Computational results are reported on examples generated from the Kuehn and Hamburger test problems.

ISSN:0160-5682    

DOI:10.1057/jors.1986.84

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractThis paper examines a sequential multiple-criteria decision problem. The problem arises when a decision-maker is unable to consider all possible decision alternatives simultaneously. The decision-maker evaluates only a subset of all decision alternatives, from which he chooses the most preferred solution. Obviously, this solution is not necessarily‘globally’best. An interesting question is: how good is the most preferred solution and what are the chances of finding a better solution by considering additional alternatives? A unified approach to solving this problem based on probability theory is presented and illustrated with numerical examples.

ISSN:0160-5682    

DOI:10.1057/jors.1986.85

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractThis paper examines some properties of generalized subtour elimination constraints and connectivity constraints used in a variety of routeing problems.

ISSN:0160-5682    

DOI:10.1057/jors.1986.86

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractThe advance of computer, automation and control technology has led to the adoption of continuous control and monitoring of production processes in high technology industries. By monitoring the state of the production process continuously, occurrence of any faults in the production process can be identified with zero or negligible detection delay. As a result, the costs of defective products, loss in yield and restoration are minimized. On the other hand, the sensitivity of the continuous monitoring system could result in very frequent repair and maintenance of the process, causing frequent disruptions of production. This paper addresses the question of the determination of the optimal level at which warning signals should be given of fault occurrences in a production system that is continuously monitored. A model is developed from which the expected total costs per time unit can be derived. A numerical example illustrates the determination of the optimal warning level under this framework.

ISSN:0160-5682    

DOI:10.1057/jors.1986.87

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractUsing generally accepted principles of financial analysis, this paper argues that, if trade credit has the character of a renewable source of capital, the usual assumptions as to the incidence and the value of the inventory investment opportunity cost made by traditional inventory theory are correct, contrary to several recent papers on this subject. It then shows that if trade credit surplus is taken into account, the optimal replenishment quantities decrease, rather than increase, as argued in some papers.

ISSN:0160-5682    

DOI:10.1057/jors.1986.88

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor