摘要:

The block sequencing strategy, where retrievals are sequenced and executed in blocks, is commonly assumed in many works on operations management in automated warehousing systems. The nearest neighbour heuristic is a popular sequencing method. In this work, the destructive effects of block sequencing on the system's performance: waiting times and queue length, in a non-deterministic environment, is demonstrated. Dynamic application of the nearest neighbour as a dispatching rule is proposed as an alternative. The performance level of the dispatching nearest neighbour rule is surprisingly high

ISSN:0020-7543    

DOI:10.1080/00207549208948162

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In order to solve a large-scale Markov decision process which optimizes the control strategy of a multistaged production/inventory system, a computation reduction and memory management system was used. A ‘nuclear’ state space of relatively small size was found to substitute for the original state space. A circular comparison technique and a location index storage method were used to save computer memory used for storing the model

ISSN:0020-7543    

DOI:10.1080/00207549208948163

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The grinding process is a very complex system for which analytical and empirical models have been developed to pursue a control strategy. This paper utilizes a new approach to model the creep feed grinding of superalloys, Ti-6Al-4V and Inconel 718, by using a neural network. A back-propagation learning algorithm is adopted to capture the system behaviour. The neural network learns to associate the inputs (feed rate, depth of cut and wheel bond type) with the outputs (surface finish, force and power) and predicts the systems outputs within the working conditions. Mathematical formulation of a multiobjective optimization problem is then carried out by utilizing the network models. The optimization study results are presented in the form of decision tables and value path diagrams to assist the decision-making process

ISSN:0020-7543    

DOI:10.1080/00207549208948164

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

FMS layout design is a complex process, involving a large number of alternatives, which contributes generously to the usual two-year FMS planning lead time. The need for a comprehensive, yet easy-to-use methodology or tool which can reduce this large number of alternatives to a more reasonable figure has motivated this research. A survey of existing FMSs was undertaken with the intention of identifying some of the more common (dominant) types of layouts, and to develop, if possible, a methodology for the selection of such layouts. However, almost every FMS was found to have a unique layout. For a given FMS under consideration, the capabilities with respect to the parts which can be manufactured is essentially given. The determining features of the resultant design of the FMS, therefore, are primarily based upon the design of the material handling system which integrates the FMS. However, as the number of machines in a FMS increase, the number of part sequences and alternate configurations increase at a dramatic rate. To assist in the preliminary design process, an interactive computer-based program has been developed to aid the search for non-inferior layouts to suit the exact part sequence needs of each FMS. Six criteria-three related to the distances parts travel during manufacturing and three related to the capital costs of the FMS-are provided to assist the user in selecting an appropriate arrangement. The program is described and its use is demonstrated in developing improved arrangements over an example FMS which was published in the literature. Although the reader is cautioned that the results were developed using only static measures, the results do indicate that significantly improved designs are possible using the proposed methodology

ISSN:0020-7543    

DOI:10.1080/00207549208948165

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

One of the fundamentals of good operations management practices that is rarely discussed in the literature is the ‘complete kit’ concept, which suggests that work should not start until all the items required for completion of the job are available. These items (the kit) include components, tools, drawings and information. Starting a job with an incomplete kit means more labour time to finish the job, longer lead time, more work in process, reduction of throughput, poor quality and impairment of due date performance. The paper analyses the various facets of the complete kit concept in manufacturing, research and development, engineering and service organizations

ISSN:0020-7543    

DOI:10.1080/00207549208948166

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The main difficulty associated with the application of graph theory to facilities layout is the conversion of the dual graph into a block layout. Hassan and Hogg (1989) presented a procedure to solve this problem. This paper gives some comments and critiques related to the problem and demonstrates that their procedure does not always work in a manner consistent with the adjacencies specified by the dual graph. In addition, rules for improving the procedure are developed. The paper is written in note format and the reader needs to refer to Hassan and Hogg (1989) for understanding the procedure and undefined notations.

ISSN:0020-7543    

DOI:10.1080/00207549208948167

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Al-Hakim (1992) claims the existence of some pitfalls with the procedure of Hassan and Hogg (1989) for converting a dual graph into a block layout. This note explains the necessary conditions in order for the procedure of Hassan and Hogg to work, and illustrates that Al-Hakim's examples were not solved because they deviated from these conditions. The note also discusses the suggestions of Al-Hakim and points out that they will not succeed in addressing all situations

ISSN:0020-7543    

DOI:10.1080/00207549208948168

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0020-7543    

DOI:10.1080/00207549208948170

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0020-7543    

DOI:10.1080/00207549208948172

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor