摘要:

This paper presents a throughput-maximizing algorithm for facility planning and layout of flexible manufacturing systems. It uses a computationally efficient mean-value analysis model to analyse system configurations, and extends the methodology of CRAFT in layout planning.

ISSN:0020-7543    

DOI:10.1080/00207548908942525

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper finds an optimal control policy for a production process that shifts randomly, but with drift, during production. The cost of deviation from the optimal setting is quadratic, and possibly asymmetric. The process may be reset at a fixed cost. Two models where the process drifts by discrete steps are explored and optimized. Use of these models to approximate continuous process shifts is discussed.

ISSN:0020-7543    

DOI:10.1080/00207548908942526

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A procedure is developed for identifying the optimum number of cavities which should be used for any particular injection-moulding task. The method is based on empirical relations for machine and mould base costs and estimates of the economics of multi-cavity manufacture. A simple rule for mould size is established to form the basis for early cost estimating in product design.

ISSN:0020-7543    

DOI:10.1080/00207548908942527

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Recent research on the scheduling of job shops has demonstrated the need for dispatching rules that are effective over a wide range of due-date tightness. In this paper a new dispatching rule is presented and compared with other prominent dispatching rules. The new rule employs shortest-processing-time (SPT) scheduling in a controlled manner: using due-date information to expedite jobs that are late or behind schedule, and employing a heuristic to control the scheduling of jobs with long processing times. Based on a simulation analysis, the rule is shown to perform nearly as well as the SPT rule with respect to mean job flowtime, and without the undesirable SPT side-effect of large conditional mean tardiness. The rule is also shown to be robust to changes in due-date tightness. In comparison with other well-known dispatching rules, its performance is generally superior with respect to mean flowtime, mean tardiness and conditional mean tardiness, with only the COVERT rule performing nearly as well. Unlike the COVERT rule, which requires the estimation of a job's remaining shop queue time, the proposed rule requires no estimation of global shop characteristics.

ISSN:0020-7543    

DOI:10.1080/00207548908942528

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In most of the literature on performance analysis of production systems, buffer are assumed to be controlled locally. In automated production systems buffers are not always the result of local physical space restrictions, but may also be software-controlled. Software-controlled buffers allow a more efficient use of the production units and a better control of the work in progress. Some of these possible control principles are known from production control and goods flow theory. We present a model for production systems in which the goods flow is continuous. The effect of different control mechanisms on the performance of the system (that is throughput and throughput time) is studied. Examples of control systems are BSC (Base Stock Control), Workload Control and control by local buffers only. It appears that for our model many of these control systems yield equivalent performance measures.

ISSN:0020-7543    

DOI:10.1080/00207548908942529

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Most American firms are concerned with improving their quality. Unfortunately, the current literature does not give a comprehensive theoretical model in order to evaluate each recommendation economically. Because of the lack of a theoretical model and the complexity of quality improvement systems, integrative efforts coordinating marketing and production have been largely ineffective in the strategies of firms, since they have not been subject to traditional cost-benefit analysis. This study develops an integrative strategic quality management theory and a cost-benefit model which put quality improvement programmes into the traditional decision-making framework. Conclusions of this study suggest that quality improvement programmes benefits are cumulative and costs are static. Consequently, evaluation of quality improvement programmes must be dynamic and integrative if they are to be properly evaluated.

ISSN:0020-7543    

DOI:10.1080/00207548908942530

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Parallel processing offers several advantages. However, when processing times are allowed to vary, it can result in unpredictable job sequences. This issue must be addressed in assembly systems where it is necessary to match specific jobs with specific materials downstream. This research analyses job sequences after parallel processing and provides strategies for dealing with jobs getting out of sequence. One strategy involves re-sequencing materials using material buffers and another involves re-sequencing jobs using job buffers. A simple analysis determines the size of material buffers. The size of job buffers is estimated using analytical approximation and formulas fitted to simulation results.

ISSN:0020-7543    

DOI:10.1080/00207548908942531

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Recent technological development in vehicle design allow vehicles to operate without physical guide paths, i.e. free-ranging automated guided vehicles. This paper addresses the problem of defining flow paths for these vehicles. A model is presented whereby the number of allowable flow paths and the flow directions between nodes (representing pickup/delivery stations and aisle intersections) of the layout network are determined. Examples are presented to demonstrate the approach.

ISSN:0020-7543    

DOI:10.1080/00207548908942532

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper discusses the development of a knowledge-based expert system (EXPIM) which can identify and recommend up to 30 production-inventory models. The user (manager) is asked a sequence of questions regarding the problem situation. The system uses backward-chaining to identify what is the correct model to use given the situation described by the user. The paper also discusses the general methodology for building expert systems in management science for the purpose of identifying models in other areas, such as queueing theory and location theory.

ISSN:0020-7543    

DOI:10.1080/00207548908942533

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The throughput capacity of an automated warehousing system is mainly dependent on two factors; the number of available storage spaces and the efficiency of the storage and retrieval system. If it is assumed that only a limited amount of resources are available to build a warehouse, spending most of the resources on providing more spaces or on a more efficient storage and retrieval system becomes a crucial allocation problem. In this paper, a warehouse consisting of two types of storage spaces, random access and rack space, is considered. Random access spaces are assumed to require more resources per unit to provide, but they contribute more to the efficiency of the operation of the system because items can be stored in and retrieved from them without delay. Rack spaces, on the other hand, need the services of a stacking crane for storage and retrieval. As a result, the queueing system formed limits their utilization. Here, a method is presented for the optimum allocation of the resources among these two types of spaces so that the overall throughput capacity of the warehouse is maximized. The problem is formulated and solved as a stochastic optimization problem and a numerical example is provided.

ISSN:0020-7543    

DOI:10.1080/00207548908942534

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor