摘要:

Just-In-Time (JIT) research has been limited primarily to descriptive works, case studies, surveys, and a few simulations and analytic models. This paper, by contrast, reports on an empirical field study exploring the relative importance of several JIT-based independent variables to the total level of supplier-linked inventory in an environment where the customer was implementing JIT. The results lend some support (as expected) to classical inventory theory, but also indicate the relative importance of the variables in this JIT environment. Open-ended discussions with customer and supplier managers lend further insights into the results.

ISSN:0020-7543    

DOI:10.1080/00207548908942669

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This study develops a set of preventive maintenance policies, based on the idea of critical machines, for use in group technology shops. These policies designated certain machines in the shop as critical. When a critical machine breaks down, it is repaired and preventive maintenance is applied to a block of machines (either the remaining machines in the cell, the other machines of the same type or all of the remaining machines in the shop). Simulation of a complex group technology shop was used to compare twelve definitions of criticality and three preventive maintenance conditions. The definition of criticality was not found to be a major cause of performance differences between shops, since in many cases, the same machines were critical by any definition. The application of preventive maintenance to all machines in the shop when a critical machine had failed led to the best shop performance, indicating that the reduction in machine interference caused by doing so was more important than the unique features of group technology.

ISSN:0020-7543    

DOI:10.1080/00207548908942670

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In this paper we consider a piece of manufacturing equipment dedicated to the production of a family of items. With known level demand rates for the individual items the policy used is to cycle through production of all of the items every T units of time. The paper addresses the choice among two adjustment options when the cost-minimizing T value leads to potential spoilage of an item because of shelf life considerations. The less obvious option of slowing the production rate of the concerned item is shown to be more cost effective than simply reducing theTvalue.

ISSN:0020-7543    

DOI:10.1080/00207548908942671

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In this article, a framework is proposed for computerization of tool-replacement decision making in flexible manufacturing systems (FMSs). Specifically, a procedure is outlined that addresses the decision of whether a tool should or should not be replaced prior to its processing of a workpart. The proposed procedure attempts to minimize the tool-related economic losses associated with these decisions while maximizing part throughput. The limitations of both the human and the computer at achieving both of these system performance objectives are discussed and form the basis to the proposed procedure. Based on a simulation study examining human capabilities at making tool-replacement decisions, various heuristics employed by humans who were successful at performing this task were identified. These heuristics as well as other considerations were incorporated into the procedure in an effort to maintain a balance between the more direct local consequences and less direct global consequences of tool-replacement decisions on the economic and throughput objectives, respectively. The article concludes with a discussion on the role of sensitivity analysis, and the use of the procedure within the context of human supervisory control of FMSs.

ISSN:0020-7543    

DOI:10.1080/00207548908942672

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In this paper an attempt is made to define and analyse the critical subsystems relationships within a manufacturing strategy. For this purpose the whole production function is described as a pressurized Venturi system in an effort to clarify complex input-output and control relationships within a typical batch manufacturing environment. The value of scheduling methods is also discussed with attention directed towards critical value added stages and throughput time in the manufacturing process.

ISSN:0020-7543    

DOI:10.1080/00207548908942673

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Numerous researchers have suggested methods for clustering machines into manufacturing cells in a Group Technology environment. Many of these methods are numerically complex. This paper presents a new linear clustering algorithm that is fast, simple and quite flexible. The algorithm is based on the calculation of a commonality score which indicates the similarity in the way two machines are used in the shop to manufacture the products or parts.

ISSN:0020-7543    

DOI:10.1080/00207548908942674

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A combined heuristic approach for dynamic lot sizing problems has been proposed. The combined heuristic is based on the performance analysis of the Silver-Meal heuristic on different problem sizes and demand patterns. The heuristic performs extremely well on average, and has a worst case performance ratio of two.

ISSN:0020-7543    

DOI:10.1080/00207548908942675

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper presents a cost-based model for capacity planning of Flexible Robotic Assembly Systems capable of handling batch assembly of multiple end products. The non-linear integer programming model is based on a specific cell design procedure that considers two important aspects, such as robot selection, and cell configuration, in forming the assembly cell. The model incorporates stochastic variations in the batch arrival rate, batch size, and processing times. The solution procedure for the model is discussed and an example problem is used to demonstrate the use of the model for real world applications.

ISSN:0020-7543    

DOI:10.1080/00207548908942676

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A model for describing form feature geometry is presented. The model treats form features as volumes enveloped by entry/exit and depth boundaries. The geometric characteristics of a feature are decided by the degree of accessibility to its volume, its boundary type, its exit boundary status and its form variation with respect to its depth axis. A hierarchical structure for form features classification is also presented. Based on their geometric characteristics, features are classified into categories, classes and sub-classes. These can be followed by secondary forms to fully describe compound features. The feature description method together with the associated hierarchy provide a very flexible model for feature description and classification. The model is of direct relevance to many of the CAD/CAM activities and contain concepts that can help to ease their integration.

ISSN:0020-7543    

DOI:10.1080/00207548908942677

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Reliable predictive formulae are presented for calculating the output efficiency of unpaced assembly lines under two conditions: one, in which all stations in the line exhibit constant variability ( Cv); the other, has one of the stations in the line having a lower coefficient of variation (COVA) than those of the other stations (Cv). The prediction models apply to various combinations of buffer capacity, processing time variability and operating strategies. Predictions of line performances are then compared with simulation data to determine their applicability for design purposes.

ISSN:0020-7543    

DOI:10.1080/00207548908942678

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor