ISSN:0160-5682    

DOI:10.1057/jors.1978.2

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractCorporate Planning is a multi-dimensional activity. It can no longer be thought of as a largely analytical process to which OR can make a contribution through its quantitative techniques. This may be a reason why Operational Researchers seem to be losing their pre-eminent position as corporate model builders. So that it can regain that position OR will have to consider constructing models that incorporate political as well as psychological variables and models that allow managers to manage.

ISSN:0160-5682    

DOI:10.1057/jors.1978.3

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThis paper describes a case-study concerning a transportation-distribution system for the world's largest flower auction in Holland. Each day, 4–8 million flowers are sold in 4 hr in approximately 20,000 transactions, each consisting of 1–250 bunches or boxes of flowers. The transactions are distributed over more than 1000 dealers. The stochastic character and the composition of the output of the auction process make it difficult to design a good transportation-distribution system. A newly implemented semi-automatic transportation system was taken out of use after only 2 weeks of operation.The operational research study shed considerable light on what was going wrong, and suggested a number of useful lines of further investigation.

ISSN:0160-5682    

DOI:10.1057/jors.1978.4

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThis paper outlines the application of a GPSS computer simulation model to the maintenance of aircraft engines in TAP the Portuguese National Airline. The engines pass through the cycle of: in service, maintenance, in stock, and eventual return to service. The authors concluded that, if better planning of the routine maintenance could be implemented, the number of engines could be reduced by two, representing a considerable saving. This failure of planning is attributed to the failure of the organization to adapt.

ISSN:0160-5682    

DOI:10.1057/jors.1978.5

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractAn extensive literature exists which suggests that operational research methodology can be applied to capital budgeting decision-making. This paper reports on the use of such techniques by some U.S. firms. The data was obtained by a questionnaire mailed in November 1974 to 1000 randomly selected firms in the U.S. that had an employee who was a member of the Operations Research Society of America.

ISSN:0160-5682    

DOI:10.1057/jors.1978.6

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractA number of decision criteria are evaluated in the context of a portfolio of investments in venture capital.The essence of this activity is that it is a sequential decision problem with stochastic time intervals between decisions, where the choice is to make an investment or not. The pay-off from the investment is a payment of random magnitude after a time interval of random length.Some of the criteria used in security portfolio analysis are adapted for use in this context and compared with simpler criteria. Due to the typically risky nature of these investments, the level of information about the investment is kept to a realistic level.The results of simulation experiments demonstrate effectively the benefit of using rational decision criteria, but that there is surprisingly little difference between the effects of these criteria.

ISSN:0160-5682    

DOI:10.1057/jors.1978.7

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractA group of experts is to produce a joint forecast of a set of unknowns. Each expert is asked to distribute subjectively a given sum of confidence weights over his own forecasts. A joint forecast is computed as the product sum of the individual forecasts and weights deduced from the individual's weights. A probabilistic interpretation of this procedure is provided and a measure of the reliability of the joint forecasts is suggested. A Bayesian variant can be constructed by introducing sample information.

ISSN:0160-5682    

DOI:10.1057/jors.1978.8

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThis paper considers the range of values of the coefficient of variation of waiting time in some general single-server queueing systems. It is shown that inM/G/1 systems with givenρ, the square of this coefficient increases linearly withm1m3/m22, wheremiis theith moment of the service distribution. This implies always a lower bound, and for some widely used distributions an upper bound as well. A few ranges are illustrated and compared to those implied in twoGI/M/1 systems. The usefulness of knowing such ranges for modelling purposes is explained.

ISSN:0160-5682    

DOI:10.1057/jors.1978.9

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThis paper considers a class of feasible set fixed-charge depot location problems which have been formulated as mixed-integer programmes. Computational results are reported to show that linear programming often produces integer solutions to uncapacitated problems as required. It is suggested that this represents a practical solution approach. Computational evidence suggests this convenient property does not extend to capacitated problems.Discussion of reducing infinite set problems to such feasible set problems is included.

ISSN:0160-5682    

DOI:10.1057/jors.1978.10

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThis paper is intended to show that the Weibull distribution can effectively be used to approximate the lead time demand in several cases of distributed demands coupled with distributed lead times. With this approximation, the computations involved are shown to be very simple, requiring no numerical or iterative procedures for determining the re-order levels or protection levels. Some pertinent properties of the Weibull distribution are summarized, and necessary tables for estimating the parameters of the Weibull distribution are given. Numerical examples are given in three cases of distributed demands and lead times and, in each case, the Weibull approximation results are compared with exact and/or other approximate results.

ISSN:0160-5682    

DOI:10.1057/jors.1978.11

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor