ISSN:0160-5682    

DOI:10.1057/jors.1967.66

出版商:Taylor&Francis    

年代:1967

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1967.67

出版商:Taylor&Francis    

年代:1967

数据来源: Taylor

摘要:

AbstractThis paper is offered as an operational research contribution to design methodology. The process of design is defined as a decision-making process where the total problem is divided into subproblems or levels of the process. Within each level, the stages of analysis, synthesis and evaluation are defined. Difficulties associated with the interdependence of decisions are described with reference to attempts of others to find systematic methods for assisting designers. The author shows that interdependence between decisions can be represented by a graph (collection of nodes and arcs) and a technique known as the analysis of interconnected decision-areas (AIDA) is introduced. AIDA can be used to determine the number of solutions and their form and, if criteria of choice are available, can be used to find optimal solutions. The use of AIDA is illustrated by an example drawn from the field of architecture and the paper concludes by indicating possible new areas where the technique may be applied.

ISSN:0160-5682    

DOI:10.1057/jors.1967.68

出版商:Taylor&Francis    

年代:1967

数据来源: Taylor

摘要:

AbstractThe reasons for endeavouring to estimate the appropriate total research expenditure in a manufacturing industry are outlined. Three techniques are discussed using an analytical, a comparative and a synthetic approach respectively. It is pointed out that the guidance given by these three techniques differs substantially in particular situations and that more studies are needed as to the relative value of the three solutions. It is suggested that an individual company should be spending about one-fifth of its future capital requirements on R.&D. The R.&D. expenditure of the U.K. should be about 4 per cent of the gross national product.

ISSN:0160-5682    

DOI:10.1057/jors.1967.69

出版商:Taylor&Francis    

年代:1967

数据来源: Taylor

摘要:

AbstractThis paper describes a case study of the reorganization of a municipal bus undertaking. The terms of reference were to consider reorganizing the route structure, to advise on frequencies to operate on the chosen routes, to compile timetables, and to design bus schedules so that the recommended system could be implemented with the minimum number of active buses. Theoretically, all of these variables can interact and one global model should be used to optimize the entire system simultaneously. In practice, the components of this problem had to be uncoupled and tackled separately. An heuristic model designed to provide a "good" route network was developed. Service frequencies were allocated to routes so that a measure of service to passengers was maximized. Bus timetables were compiled using conventional methods and a linear programming model used to assign individual buses to journeys. A new scheme based on the recommendations of the study has been implemented. It is expected that it will reduce the annual operating deficit by [pound]35,000 without appreciably decreasing the overall level of service offered.

ISSN:0160-5682    

DOI:10.1057/jors.1967.70

出版商:Taylor&Francis    

年代:1967

数据来源: Taylor

摘要:

AbstractThis paper describes an operational research approach to planning the restoration of an open-cast coal site.No established operational research technique exactly fitted the problem, which was one of planning a large-scale earth-moving operation, where the quantities to be moved were not specified, but had to be planned to conform with stringent restrictions on gradients, continuity, drainage and total volume. A numerical technique was developed, used in conjunction with the dual solutions of successive transportation programmes to reach progressively an optimum solution.The nature of the problem allowed an unusually clear-cut comparison to be made between the previous conventional plan and the operational-research-based plan; the latter showed considerable savings and was put into practice.There would appear to be many other situations where the approach could be applied.

ISSN:0160-5682    

DOI:10.1057/jors.1967.71

出版商:Taylor&Francis    

年代:1967

数据来源: Taylor

摘要:

AbstractA method is described of allocating funds between projects in a firm with the following characteristics: most investments are financed from internal sources; reasonable predictions can be made of investment opportunities arising several years ahead; management wishes to take account of the way the allocation will affect other published financial results besides cash flows. A numerical example shows how each allocation affects return on gross assets, current ratio and profit after tax in successive years. These measures are related in a linear programming formulation. The solution demonstrates how particular projects may attract funds by offering ways of altering published results. Related solutions show how the existence and timing of future opportunities affect the optimal current allocation and the value of the programme. Criteria are also developed for whether and when to borrow. It is shown that the returns to incremental borrowing may be much greater than the returns on any available investment considered in isolation, and may fall to zero although profitable single opportunities still exist.

ISSN:0160-5682    

DOI:10.1057/jors.1967.72

出版商:Taylor&Francis    

年代:1967

数据来源: Taylor

摘要:

AbstractThe aim of this paper is twofold: (1) to offer another proof of the theorem, established by S. L. Hakimi, in which it was shown that the optimal locations of uncapacitated centres on a linear graph are always at the nodes of the graph; (2) to extend the result to the case of concave, and not necessarily identical, transportation cost functions and to centres with capacity restrictions.

ISSN:0160-5682    

DOI:10.1057/jors.1967.73

出版商:Taylor&Francis    

年代:1967

数据来源: Taylor

摘要:

AbstractThis paper investigates the situation where a joint replenishment order for a group of stock lines from a common supplier qualifies for a quantity discount provided the total order equals a specified number of units. It is assumed that, when any line in the group reaches its reorder point, an order of this size is made for the whole group and it is the problem of how to determine the optimum order "mix" which is considered here. In the case of a group consisting of two lines only, an analytical solution is derived which, assuming Poisson sales-rates, gives the individual stock levels for which the expected number of sales between successive replenishments is maximized for a given total stock. However, for groups of more than two lines, it was necessary to resort to numerical methods and a computer program is described which uses a quasi dynamic-programming approach to determine the optimum set of individual stocks for any given set of sales-rates and total stock. Based on the results from this program, a "ready reckoner" has been constructed which permits an easy look-up to obtain the optimum allocation of any given total stock between the lines of a group of any size and sales-rates. Finally, the possible extension of this approach to other multi-item inventory problems is discussed.

ISSN:0160-5682    

DOI:10.1057/jors.1967.74

出版商:Taylor&Francis    

年代:1967

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1967.75

出版商:Taylor&Francis    

年代:1967

数据来源: Taylor