摘要:

AbstractThis paper sets out the case for OR workers embarking on the construction of models of wider scope than has been traditional. Changing industrial conditions emphasize the need to include the social costs of absenteeism, high labour turnover, training and indifferent quality in the evaluation of new projects, as well as the influence on productivity of these factors, and, more especially, of the means devised to overcome them. New criteria of effectiveness are required.A plea is made for OR to be involved in model building of the new patterns of industrial organization; such models could help the uncommitted countries to explore the alternatives at factory and union levels. A comprehensive model would therefore need also to quantify the effect of alternative union structures and strategies on industrial output and on the living standards of the workers.Quantification presents formidable difficulties but to avoid such problems would condemn OR to a role of perpetual sub-optimization.

ISSN:0160-5682    

DOI:10.1057/jors.1978.46

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractA group of operational researchers and managers were questioned on the degree of managerial involvement in a project with which they were concerned. From these data, a management participation score was developed for each project, and the studies were divided into three groups: (1) unsuccessful, (2) successful but unimplemented, and (3) successful and implemented. No significant differences were found between analysts' and managers' perceptions of the degree of managerial participation, but analysts perceived a higher percentage of the successful studies as being implemented. When the data were divided into linear programming and other studies in order to be analysed separately (thereby adjusting for perceptual effects of different techniques), significantly higher participation scores were found for successful and implemented studies as compared to the scores for successful but unimplemented studies.

ISSN:0160-5682    

DOI:10.1057/jors.1978.47

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractOur highly complex and increasingly expensive health service systems require management and planning on an area-wide or regional level. In this paper a medical resources allocation decision-making aid which is explicitly attuned to the needs of a regional planning body is described. Specifically, a linear programming production model of a diagnostic radiology department is presented. This model was developed to support the radiographic equipment allocation decisions of the Quebec Ministry of Social Affairs.The outstanding advantage of this approach in terms of implementation is its conceptual simplicity. In particular, the model is merely a multi-dimensional extension of the simple input-output models already used in the decision environment we examined. The model was developed to provide planners with a means of evaluating the relative technical efficiencies of the members of a group of producers and is currently in trial use.

ISSN:0160-5682    

DOI:10.1057/jors.1978.48

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractTraditional decision-making techniques only deal with a limited type of uncertainty: that which can be foreseen sufficiently to be expressed as a number of alternate moves between which nature will choose. A plan is formulated which specifies how the decision-maker should respond to nature's moves. Such a plan makes no allowance for uncertainty which could not be foreseen. Unforeseeable uncertainty can only be dealt with if the decision-maker's response to nature's moves is not fixed in advance but is itself uncertain. Flexibility is then defined as the entropy of that uncertainty. It is a measure of both the number of alternative sequences of moves which are open to the decision-maker and his attitude to them. Robustness is a way of trading off flexibility against expected value as estimated under foreseeable uncertainty. The cost of flexibility may be estimated and controlled.

ISSN:0160-5682    

DOI:10.1057/jors.1978.49

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractIn this paper it is shown that the combinatorial problem of scheduling jobs of equal duration with tardiness costs and resource limitations can be solved by formulating the problem as a classical transportation model which is here highly degenerate. A new algorithm derived from the classical stepping stone method is given. The algorithm produces a strict decrease of the objective at each iteration. A special case which could be called the simplest problem of scheduling is also studied.

ISSN:0160-5682    

DOI:10.1057/jors.1978.50

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThis paper considers the problem of optimally controlling a finite state production process subject to deterioration where the decisions available to the inspector are: produce without inspection, produce with inspection, and repair. The state of the production process is perfectly observed at times of inspection and completely unobserved otherwise. If the production process has an increasing failure rate and if certain reasonable assumptions are satisfied by the cost structure, it is shown that optimal strategies for the finite horizon, discounted cost, and average cost cases have certain structural properties which correspond to the well-known four-region description of the optimal policy presented by Ross for the two-state case. These results are also shown to be similar to those recently determined by Rosenfield and are proven under weaker assumptions.

ISSN:0160-5682    

DOI:10.1057/jors.1978.51

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThe importance of the covariance of returns between capital assets is one of the basic principles of modern portfolio theory. An investor should seek capital assets which have negative covariance of returns, or if such capital assets are not available, capital assets with low covariance should be sought for a portfolio. From the variance-covariance structure of returns of the capital assets and the expected returns for each capital asset, a risk-reward trade-off or efficient frontier can be generated. The trade-off represents the minimum risk, as measured by portfolio variance, that could be incurred to realize a desired rate of return for the portfolio. This concept applies to a portfolio of capital budgeting projects as well as to a portfolio of securities. This paper demonstrates how this concept of portfolio diversification can be applied to a capital budgeting problem. The problem involves an actual problem faced by a U.S. distributor who must decide whether to expand sales into one of two industries. Quadratic programming is used to generate the risk-reward relationships and it is shown that the entry into one industry clearly provides a superior risk-reward relationship than entry into the other industry and compared to the company's present sales policy.

ISSN:0160-5682    

DOI:10.1057/jors.1978.52

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThis paper presents a practical approach for studying the profit probability distribution defined in stochastic breakeven analysis. After presenting a procedure for calculating the mean and the second to fourth central moments of the profit distribution, the several important uses of these four moments are discussed. A major application of the four moments is in the fitting of a Pearson's curve. Using a numerical example in conjunction with a set of published tables, we then demonstrate the simplicity of our proposed approach as well as the resultant high accuracy in estimating probabilities of various profit levels.

ISSN:0160-5682    

DOI:10.1057/jors.1978.53

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractIn the allocation of resources to activities, each activity is described by a concave return function and the sum of the returns is maximized. There are linear constraints on the available quantity of each essential resource. Existing methods for the incremental generation of almost-optimal allocations and for the evaluation of such allocations are extended to include allocations involving "noise" constraints in addition to the linear constraints on the available quantity of each resource. A noise constraint, which is defined in the paper, may be expressed by any relationship, not necessarily linear. An example is given in which the noise constraints take the form of constraints on additional resources.

ISSN:0160-5682    

DOI:10.1057/jors.1978.54

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractAn optimal control problem is formulated with a simple epidemic model in which the control of the epidemic is effected by varying the scale of the quarantine program in a way which minimizes a discounted linear cost over an infinite horizon. An important function of the problem parameters is identified. It is shown that if this function has a value of less than or equal to one, then the optimal policy is not to quarantine at all. While if this functions assume a value in excess of one, then the optimal policy is not to quarantine at all if the initial fraction of infectives is sufficiently high; otherwise, it is optimal to have a full scale quarantine program. Slight modification in these policies are required for the finite horizon version of the problem.

ISSN:0160-5682    

DOI:10.1057/jors.1978.55

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor