摘要:

In the wake of airline deregulation, most carriers have been forced to reexamine both their pricing strategies and operating schedules. With reference to the latter, one of the factors that has been largely overlooked as a source of additional revenue is the convenience of a through flight over a connecting flight. The purpose of this paper is to explore this issue by developing an algorithm that can be used to effectively pair inbound and outbound routes at hub cities over the course of the day. We take the view that if demand is dependent from one period to the next then significantly higher revenues can be realized by making appropriate adjustments in the scheduling algorithm.

ISSN:0740-817X    

DOI:10.1080/07408178708975393

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

We consider multistage automatic transfer lines with unreliable stages, finite interstage buffer storages, and possible scrapping of workpieces. It is assumed that the first stage never idles and the last stage never becomes blocked. Assuming that uptimes and downtimes of a stage are geometrically distributed, an approximate model is developed to compute different performance measures of the transfer line. The results obtained through the approximate model are compared to the exact results for three-stage transfer lines and to simulation results for longer transfer lines. It is observed that the approximate results are good in almost all cases considered.

ISSN:0740-817X    

DOI:10.1080/07408178708975394

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Machine-component grouping is a basic step in the application of group technology to manufacturing. It is the process of finding families of similar parts (part-families) and forming the associated machine cells such that one or more part-families can be processed within a single cell. Among the algorithms used to form the machine cells, those based on the Similarity Coefficient Method (SCM) are more flexible in incorporating the manufacturing data into the machine-component grouping process. SCM is the application of clustering techniques in forming the machine cells. One of the major problems with SCM is that it generates a set of alternative solutions rather than a unique solution. The number and size of machine cells in a given solution depends upon the similarity coefficient (threshold value) at which machine cells/machines are joined. This paper discusses the problem of selecting a proper threshold value and presents a solution to it.

ISSN:0740-817X    

DOI:10.1080/07408178708975395

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This paper is concerned with the development of an interactive block layout system which utilizes b-matching as the optimization component. The objective function utilized by the b-matching is to maximize a weighted sum of adjacent departments. The b-matching model is a relaxation of the layout problem, hence human interaction is critical to overcome the factors not captured by the model.

ISSN:0740-817X    

DOI:10.1080/07408178708975396

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Over the last 18 years the Center for Ergonomics at The University of Michigan has worked to develop a computerized, biomechanically based model to predict worker muscle strengths in various tasks. During the last few years new input strength data has been acquired from published works of others. Worker isometric strength testing also has been performed by the Center in various industries to determine gross lifting, pushing and pulling capabilities of a heterogeneous group of men and women. These data, acquired from 1577 men and women are compared to the strength predictions of the biomechanically based model. For prediction of mean strength capabilities of both men and women performing varied types of symmetric sagittal plane exertions, the model results were relatively unbiased and were well correlated withr2between 0.85 and 0.88 with the population data. The results were not as good for predicting the mean strengths of two-handed assymetric exertions (r2between 0.54 and 0.74), and for one-handed, sagittal plane exertions (r2= 0.50). The utility and limitations of such a modelling approach to human strength prediction are discussed.

ISSN:0740-817X    

DOI:10.1080/07408178708975397

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Many authors have proposed models for the optimal design of control charts for the control of the defect rate for industrial processes. These models have limited the alternatives available subsequent to sampling to either rebuilding the process, or continuing to operate the process in its current state. Although the cost of rebuilding the process is treated as an adjustable parameter in these models, it can not be a negligible amount. If it were, the obvious optimal strategy would be to rebuild the process, possibly without samplings, after each batch or unit produced. This paper considers the determination of the optimal sample size and sample interval for the case where the process does not have to be rebuilt, but rather may be simply adjusted at a nominal cost after each sample. A model, which assumes a continuum of process fraction defectives, is developed and then used to explore the effect of fixed and variable sampling cost, specification limits and measurement errors on the optimal sampling policy and costs.

ISSN:0740-817X    

DOI:10.1080/07408178708975398

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The (5, 7) cyclic staffing problem is the problem of finding the least number of workers assigned to a 7 day cyclic schedule, so that sufficient workers are present during dayito meet requirementbiand each person works a shift of 5 consecutive days and is idle for the other 2. In this paper we derive an expression for the minimal workforce size in the problem in terms of thebi's. This result is interesting because it shows the extra number of workers needed by insisting that each person's idle days are consecutive.

ISSN:0740-817X    

DOI:10.1080/07408178708975399

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

We investigate the problem of setting planned leadtimes in serial production systems when the actual leadtimes are stochastic. The objective is to minimize the sum of inventory holding costs, rescheduling costs arising from tardiness at intermediate stages of production, and tardiness of delivery to the customer.

ISSN:0740-817X    

DOI:10.1080/07408178708975400

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In recent years there has been increased interest in the design and implementation of economically based sampling plans, especially those which consider a prior distribution of defectives in lots submitted for inspection. Sampling plans which are designed using this prior knowledge are often referred to as Bayesian sampling plans. This paper illustrates an approach to the design of Bayesian sampling plans which considers two criteria. The few previous attempts to design multiobjective Bayesian sampling plans have been based on expected values of the criteria. In this paper the authors present a design methodology which takes into consideration the distribution functions of the criteria after sampling inspection, and the utility function of the 'decision maker'. Illustrative examples of the use of the methodology are given as well as areas for further research.

ISSN:0740-817X    

DOI:10.1080/07408178708975401

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This paper deals with the design of priority rules for job shops that process multi-level assembly jobs. Specifically, it explores the means by which the structural complexity of jobs can be incorporated explicitly into priority rules to reduce job lead times. The job lead time is viewed as consisting of two components: flow time and job staging delays. The primary focus of the paper is on the development of a class of priority rules that is aimed at reducing the staging delay. The class of priority rules that is developed is then used in combination with rules that are effective for the flow time component. The combined rule results in the improvement of the lead time performance. The paper also includes experimental results on sets of jobs of varying degrees of complexity. These results provide a comparative perspective on the performance of priority rules that have been examined in the earlier research literature as well as the rules specifically developed in this paper.

ISSN:0740-817X    

DOI:10.1080/07408178708975402

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor