ISSN:0160-5682    

DOI:10.1057/jors.1972.46

出版商:Taylor&Francis    

年代:1972

数据来源: Taylor

摘要:

AbstractThe application of O.R. to policy-making at high levels implies a recognition that such decisions generally involve multiple criteria. The need to be able readily to change the weighting of these criteria in a model calls for a decision-making dialogue between the decision-maker and the model. This is discussed, and related to the development of on-going systems where the model is fitted into an organization to serve decision needs on a continuing basis.

ISSN:0160-5682    

DOI:10.1057/jors.1972.47

出版商:Taylor&Francis    

年代:1972

数据来源: Taylor

摘要:

AbstractIt is the purpose of this article to review the various solutions that have been proposed for the resource-constrained project scheduling problem. An attempt is made to give the state of the art to date, as well as to poinit out potential future courses of development. Emphasis is placed on the basic approach involved in each technique rather than on the computational steps required to obtain a solution. In principle the review is limited to solution techniques described in the literature; other important work will be treated also, as far as it is known to the author.

ISSN:0160-5682    

DOI:10.1057/jors.1972.48

出版商:Taylor&Francis    

年代:1972

数据来源: Taylor

摘要:

AbstractDiscontinuities may occur in the distribution cost function for a variety of reasons. Some of these, notably discontinuous trunking costs and depot costs dependent on location, have been examined in the literature. In this paper the problem which arises when discontinuities occur in the local delivery cost function is examined and a method of solution incorporating heuristics is described. An illustrative example is given.

ISSN:0160-5682    

DOI:10.1057/jors.1972.49

出版商:Taylor&Francis    

年代:1972

数据来源: Taylor

摘要:

AbstractExponential smoothing is frequently used for the forecasts in stock control systems. The analysis given shows that intermittent demands almost always produce inappropriate stock levels. Demand for constant quantities at fixed intervals may generate stock levels of up to double the quantity really needed. A method of overcoming these difficulties is described, using separate estimates of the size of demand, and of the demand frequency. The rules for setting the safety stock levels have also to be adjusted before consistent protection can be obtained against being out of stock.

ISSN:0160-5682    

DOI:10.1057/jors.1972.50

出版商:Taylor&Francis    

年代:1972

数据来源: Taylor

摘要:

AbstractThis paper describes a mechanism for aiding the designer in generating an efficient and flexible provision of teaching space to match the complex and varying needs in comprehensive schools. The mechanism is a computer program package which comprises three parts: SECS A which outputs schedules of accommodation for any given set of group activity data: SECS B which appraises any existing schedule of accommodation in relation to the minimum; and SES C which identifies the minimum physical flexibility necessary to achieve any set of alternative future accommodation schedules.

ISSN:0160-5682    

DOI:10.1057/jors.1972.51

出版商:Taylor&Francis    

年代:1972

数据来源: Taylor

摘要:

AbstractThe optimization problem of minimizing the completion time in flow-shop sequencing with an environment of no intermediate storage is considered. Application of this problem in computer systems is pointed out and techniques are developed to solve the problem.

ISSN:0160-5682    

DOI:10.1057/jors.1972.52

出版商:Taylor&Francis    

年代:1972

数据来源: Taylor

摘要:

AbstractThe problem of scheduling delivery vehicles from a number of depots to customers, subject to constraints on load and distance or time, is considered. A new algorithm is presented; this allows routes from several depots to be constructed simultaneously, subject to restrictions on numbers of vehicles at individual depots. Where too many customers require service, a flexible priority rule will select those to be served. Results for the single depot case are compared with other known algorithms; further results are given and discussed for cases of several depots.

ISSN:0160-5682    

DOI:10.1057/jors.1972.53

出版商:Taylor&Francis    

年代:1972

数据来源: Taylor

摘要:

AbstractPERT and CPM are two valuable tools for the planning, scheduling and controllingof projects, but they do not on their own deal with the interdependence between planning resource utilization or direct cost expenditure and sclheduling with its overhead cost (penalty cost and/or reward bonus) implications. Several approaches to overcome this deficiency are possible, this paper dealing with one known as Decision CPM. The most recent approach to the Decision CPM problem known to the authors leads to relatively large integer programming problems which are solved as such. This paper considers a restricted formulation of the Decision CPM problem in an integer programming framework, and shows how it may be solved relatively easily witlhout resort to integer programming methods. Extensions of the restricted model are also considered briefly, some of which pose no difficulties, while others suggest the need for a hybrid of other approaches and that described here.

ISSN:0160-5682    

DOI:10.1057/jors.1972.54

出版商:Taylor&Francis    

年代:1972

数据来源: Taylor

摘要:

AbstractThe relative performance of several sequential methods of planning multiple delivery journeys has been tested on batches of problems which varied in size, journey restrictions, delivery pattern and depot location.The saving criterion, of the methods tested, produced the best results for the conditions tested and required less than 0·1 min CDC 6600 central processor time for a 400 delivery problem; the time required varied asN1·6whereNis the number of deliveries.The relative performance of different methods varied considerably both between problems conforming to the same specifications and between batches of problems with different specifications.To compare the performance of different methods for any but extremely limited purposes, samples of results for a variety of conditions are needed; even so, in the absence of an explanation for the performance variations, only tentative conclusions are possible.

ISSN:0160-5682    

DOI:10.1057/jors.1972.55

出版商:Taylor&Francis    

年代:1972

数据来源: Taylor