摘要:

AbstractMoving from Operational Research to Corporate Planning within one organisation is a rather modest change, which nevertheless leads to a different perspective. While still an advisory function, Corporate Planning, to be successful, has to maintain itself at the centre of a `messy' system tackling `messy' problems. Holding on to a clear strategy in such circumstances is not only difficult but vital. The success of the strategy depends on its robustness and ability to adapt to new circumstances. Recent debates in the O.R. literature have focused on the importance of robustness and the nature of uncertainty using the paradigms of rational and bureaucratic processes. This is a useful perspective from which to view our activities and the relative roles of Operational Research and Corporate Planning, either separately or together. The term `mature' O.R. is used to differentiate research that has been built up over many years in the N.C.B. from the problem solving activity often used to characterise O.R. The challenge is to prevent maturity developing into old age.

ISSN:0160-5682    

DOI:10.1057/jors.1983.113

出版商:Taylor&Francis    

年代:1983

数据来源: Taylor

摘要:

AbstractAn attempt has been made to characterise small batch-manufacturing firms by material ordering and production scheduling practices. Four characterisations of classifications of small batch manufacturers have been defined with their corresponding parameters of relevance. Hypotheses of the bases of the systems observed are proposed and contrasted with traditional textbook approaches. Outlines of decision-making policies are proposed.The paper includes accounts of four of the thirteen firms visited in connection with this investigation and describes how these experiences fit the methodology used.

ISSN:0160-5682    

DOI:10.1057/jors.1983.114

出版商:Taylor&Francis    

年代:1983

数据来源: Taylor

摘要:

AbstractThe article involves an account of a simulation study undertaken to determine the best investment plan and the best investment year for Istanbul seaport. The best investment plan is defined to be the alternative with minimum total cost, which is the sum of investment costs and ship waiting time cost discounted to their present value. Investment alternatives considered consist of the construction of a new port, construction of a new berth for the existing port and construction of hinterland warehouses. An attempt has been made to determine the best quay length, number of cranes and warehouse capacity for the new port. The sensitivity of the best investment plan and year to different demand levels is studied. Next, another experiment is conducted to determine the effect of increased efficiency on investment requirements. In all experiments total cost is determined with three levels of inflation and three levels of devaluation rates using three levels of discount factors.

ISSN:0160-5682    

DOI:10.1057/jors.1983.115

出版商:Taylor&Francis    

年代:1983

数据来源: Taylor

摘要:

AbstractThis paper considers the medium-term production smoothing problem for the injection moulding department of a Belgian firm. The problem is formulated as a series of one machine capacitated dynamic lot sizing problems, which are then solved by heuristic procedures. Computational results for real-life data are presented. It follows that the capacitated lot sizing approach succeeds in smoothing production such that subcontracting, which was often necessary with the E.O.Q. approach used by the firm, could be avoided in the future. Moreover, total set-up and inventory costs are reduced by about 20%.

ISSN:0160-5682    

DOI:10.1057/jors.1983.116

出版商:Taylor&Francis    

年代:1983

数据来源: Taylor

摘要:

AbstractSchool timetabling problems containing multiple period lessons are formulated in terms of the colouring of composite graphs. Several approximate colouring algorithms are proposed and compared empirically.

ISSN:0160-5682    

DOI:10.1057/jors.1983.117

出版商:Taylor&Francis    

年代:1983

数据来源: Taylor

摘要:

AbstractThe feeding policy of a pig production unit affects both the cost of production and the weight and carcase composition of the pigs produced. Since the market value of the pigs produced is determined by the weight and composition of the carcase, feeding policy has a major influence on the economic performance of the unit. In order to evaluate possible feeding policies, the effect of feed intake on both the weight and the body composition of the growing pig must be known, and since an optimal policy will involve using least cost rations, it must be possible to determine the least cost rations to produce liveweight gains of specified body composition. A dynamic programming model to determine the optimal feeding policy to produce pigs of specified weight and carcase composition is developed using a published pig growth model which allows the formulation of the required least cost rations, and the use of this dynamic programming model is illustrated.

ISSN:0160-5682    

DOI:10.1057/jors.1983.118

出版商:Taylor&Francis    

年代:1983

数据来源: Taylor

摘要:

AbstractA long-term planning model for a large New Zealand dairy company is described. The model presents an integrated view of the company's operation, including transportation and processing. The model used is based on a network formulation, NETPLAN, developed by the authors to carry out the optimisation. NETPLAN is highly flexible, interactive and provides graphical output of the results. The optimisation maximises net revenue based on product prices, variable process costs and variable transport costs subject to factory capacity, product demand and raw material supply constraints.

ISSN:0160-5682    

DOI:10.1057/jors.1983.119

出版商:Taylor&Francis    

年代:1983

数据来源: Taylor

摘要:

AbstractA stochastic linear programme with chance constraints is considered. By allowing for the possibility of sampling, a so-called dynamic statistical decision model is developed, and the existence of an optimal decision rule is shown under appropriate continuity and compactness assumptions.

ISSN:0160-5682    

DOI:10.1057/jors.1983.120

出版商:Taylor&Francis    

年代:1983

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1983.121

出版商:Taylor&Francis    

年代:1983

数据来源: Taylor

摘要:

AbstractIn this paper an attempt has been made to generalise Dave's results on an inventory model for deteriorating items. He has derived the results for optimal order level and lot size, considering a deterministic constant demand throughout the scheduling period. Here, a variable known demand is taken to show that the optimality conditions for the optimal initial stock do not depend on the nature of the demand. A numerical example is used to illustrate the analysis.

ISSN:0160-5682    

DOI:10.1057/jors.1983.122

出版商:Taylor&Francis    

年代:1983

数据来源: Taylor