摘要:

In this paper we consider the cell formation in a manufacturing environment where there are signficant sequence dependent setup times and costs. The trade-off between saving on sequence dependent setup costs and additional investment on new machines is considered for determining the economic number of cells. Accordingly, we develop a mixed integer program and mention a variety of manufacturing situations where this model can be useful. We also include an illustrative example

ISSN:0020-7543    

DOI:10.1080/00207549208942953

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In a previous study, we began the process of examining how finite tooling resources affect the operation of a simulated job shop. The paper extends this line of research by focusing on the problem of how to schedule a shop operating with both finite machine and tooling resources, and faced by varying levels of tooling-related sequence dependency in the setups. Four tool assignment rules and two dispatching procedures are evaluated. Findings show the importance of using tool assignment rules which consider not only tool-related information such as tool availability but also the priority of the jobs waiting to be processed. Specifically, as the level of sequence dependence increases and the availability of tooling decreases, the performance of the shop is greatly influenced by the tool assignment rule used to manage the flow of tooling to and from work centres

ISSN:0020-7543    

DOI:10.1080/00207549208942954

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

One of the important issues in the design of an automated guided vehicles system (AGVS) is the determination of the number of vehicles needed to operate the system in an efficient and economical way. In this paper a multi-criteria optimization model is developed using two goals, cost and throughput performance. By using a trade-off ratio between the goals the number of AGVs needed in the systems is determined. Use of management decision tables to enhance the solution procedure is introduced

ISSN:0020-7543    

DOI:10.1080/00207549208942955

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This research project examines the performance of job shops with different machine layouts and production control systems. Job shops examined in this study operate in a make-to-order environment. Results indicate that the material requirements planning order-release-and-due-date-assignment procedure always performs better than that of the period batch control. Cellular layout, however, performs better at a high setup-to-processing-time ratio, while the process layout performs better at a low setup-to-processing-time ratio

ISSN:0020-7543    

DOI:10.1080/00207549208942956

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The high potential of using group technology in manufacturing has attracted the interest of both practitioners and researchers. Group technology is based on clustering parts which have similar features. Very often it is very hard to quantify successfully data regarding these features. This is because in many real applications features are fuzzy. This paper identifies two types of fuzzy features: qualitative features, and quantitative ones with subjective meaning. The paper presents a methodology for quantifying the data that refer to the fuzzy features. The proposed methodology deals with crisp and fuzzy data in a unified manner. Finally, some clustering approaches which process the quantified features are also discussed

ISSN:0020-7543    

DOI:10.1080/00207549208942957

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Optimum path planning of manipulator arms in assembly applications involves the selection of the optimum combination of the robot control variables under the constraints imposed by the robot's physical capabilities and the condition of the working area. The present paper describes an approach based on numerical optimization techniques to plan collision-free paths, and on Taguchi parameter design methodology to optimize the control parameters of the pick-and-place operation that would yield minimum cycle time

ISSN:0020-7543    

DOI:10.1080/00207549208942958

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A production situation is considered in which different items are produced on one machine. Setup times are incurred between the production of orders of different items. Production is driven by customer orders; each order concerns a batch of one product type and is furthermore completely characterized by its batchsize and (customer determined) due-date. Acceptance of orders may be refused if these orders are likely to cause late deliveries. The problem is to determine good acceptance strategies which naturally raises the question on what information such acceptance decisions have to be based. Three basic approaches are explored in this paper. In the monolithic approach, the acceptance decision is based on detailed information on a current production schedule for all formerly accepted orders. In the hierarchic approach, the acceptance strategy is based on global capacity load profiles only, while detailed scheduling of accepted orders takes place at a lower level (possibly later in time). In the myopic approach the acceptance decision is similar to the one in the hierarchic approach but scheduling is myopic, i.e. once the machine becomes idle only the next order to be produced is actually scheduled. The performances of these three approaches are compared by means of simulation experiments. The results indicate that the differences in performance are small. Insofar as the monolithic approach performs better, this is mainly due to the selective acceptance mechanism implicitely present in case of a heavy workload. An adaptation of the myopic approach to incorporate such a selective acceptance mechanism leads to a comparable performance

ISSN:0020-7543    

DOI:10.1080/00207549208942959

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In this paper, we address the flowpath design issue of automated guided vehicle systems (AGVSs). In particular we concentrate on the design of unidirectional flowpaths (i.e. vehicles are restricted to travel only in one direction along a given segment of the flowpath). We have developed five different heuristics for the design of unidirectional AGVSs. We have also developed simulated annealing algorithms for the above problem. Our extensive computational results indicate that a composite heuristic (i.e. one that combines the most successful of our five heuristics) yields solutions of comparable quality in a fraction of the time required by simulated annealing. For large-size flowpath design problems, we advocate the usage of composite heuristics over simulated annealing, and in particular for the cases in which inaccurate estimates for the input data in our design problem exist

ISSN:0020-7543    

DOI:10.1080/00207549208942960

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This paper presents a neural network clustering method for the part-machine grouping problem in group technology. Among the several neural networks, a Carpenter-Grossberg network is selected due to the fact that this clustering method utilizes binary-valued inputs and it can be trained without supervision. It is shown that this adaptive leader algorithm offers the capability of handling large, industry-size data sets due to the computational efficiency. The algorithm was tested on three data sets from prior literature, and solutions obtained were found to result in block diagonal forms. Some solutions were also found to be identical to solutions presented by others. Experiments on larger data sets, involving 10000 parts by 100 machine types, revealed that the method results in the identification of clusters with fast execution times. If a block diagonal structure existed in the input data, it was identified to a good degree of perfection. It was also found to be efficient with some imperfections in the data

ISSN:0020-7543    

DOI:10.1080/00207549208942961

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The answer to the above question may seem obvious: whichever of the two is the bottleneck, and if there is none, whichever of the two has longer ‘service times” and/or larger variation in service times. As we empirically show in this study, the answer is not quite so obvious. In fact, our simulation results suggest that, as long as there are no bottlenecks in the system, the material handling system should almost never be responsible for work-in-process even if it has service time parameters that are comparable to processing times at the workstations. In the paper we first show the simulation results, and subsequently we provide insight based on well-known analytical results in queueing theory. We also discuss certain properties of the workstations and the handling system that affect the work-in-process levels

ISSN:0020-7543    

DOI:10.1080/00207549208942962

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor