摘要:

This study views the conversion processes to cellular manufacturing as an aggregation of cause-and-effect relationships among many strategic, managerial, and technical variables. Successful conversions to cellular manufacturing systems require that management, fully understand these interacting variables and possible relationships between the variables. The purpose of this study is to assist such management's needs in part. The objectives of this research are (1) to explore contingency variables that may affect manufacturing cell design processes and outcomes, and (2) to seek relationships between selected contingency variables and the cell design processes and outcomes. Literature review and the mail survey method were used. The results were compared and synthesized with findings of previous studies for drawing useful discussions. Some previous arguments and propositions were empirically supported. For example, many organizational constraints are related to cell design outcomes.

ISSN:0020-7543    

DOI:10.1080/00207549608904980

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Through interviews conducted in the UK and Japan this research examines and rates the problems and the differences between two UK and two Japanese companies which are suppliers to Toyota Motors in Toyota City Japan, and Toyota Motor Manufacturing UK Ltd in Derby. This information, in conjunction with relevant examples of problems which Japanese transplant operations have encountered in the United States, is used to anticipate the range of problems that Toyota need to address when operating in the UK. As a consequence, problem scenarios with Japanese transplants are posed and possible solutions are offered.

ISSN:0020-7543    

DOI:10.1080/00207549608904981

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Building on previous research in the area of hierarchical production planning and rolling schedules, this paper is concerned with the disaggregation of aggregate plans to a rolling horizon master production schedule when production lot-sizes require minimum batch-size production. Actual data from a process industry firm is used to test and validate the proposed rolling horizon master production scheduling model. The paper also examines the impact of forecast windows on the performance of a rolling schedule when production quantities of individual product items are based on minimum batch-size production. Results indicate that the model's performance is superior to actual company performance in terms of total cost and increasing the length of the forecast window can increase costs.

ISSN:0020-7543    

DOI:10.1080/00207549608904982

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This article addresses the problem of reducing the tardiness and percentage of delayed jobs through a combination of the dispatch rule and assignation of due dates. The consideration of the time needed for jobs in the shop facilitates the organisation of the materials and resources and the fulfilment of the due dates, and it also allows the jobs that have to be urgently processed to be identified. The aim of this article is to present a rule for the assignation of due dates based on simulation. A procedure to insert idle time, which controls the progress of the jobs that may not be completed on time, is also proposed.

ISSN:0020-7543    

DOI:10.1080/00207549608904983

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Workshop real time scheduling is one of the key factors in improving manufacturing system efficiency. This is especially true for workshops in which various products are processed simultaneously, and use multipurpose machines. Real time scheduling is appropriate to handle perturbations in the environment of the manufacturing process, a major issue at the shop floor level. The products to be processed have release times and due dates and the resources are multipurpose machines. A decision support system for real time scheduling is described. It is based on an original approach, aiming at searching for characteristics of a set of schedules compatible with the main manufacturing constraints to be satisfied. This set of schedules is obtained by defining sequences of groups of permutable operations for every resource. A method to find such a set is described. We emphasize the use of this group sequence as a decision support system. Significant states and events requiring real time decisions are identified and three main types of decisions are analysed. For each of them, the proposed decision support system is detailed and explained.

ISSN:0020-7543    

DOI:10.1080/00207549608904984

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A relatively new approach which simplifies the management and control of inventory and also reduces inventory is component commonality. Due to its promising results both companies and academicians found interest in this approach. A common assumption made in previous studies is that the demands of the various products are independent. However, it is not uncommon for companies to offer products that are complementing or substituting each other. In this paper the assumption of independent demands is relaxed and the effect of products' demands correlation (positive or negative) on the performance and attractiveness of component commonality is studied. In order to obtain closed form solutions a correlation between uniform distributions is introduced. This work shows that when component commonality is being considered, demands' correlation should not be neglected due to its significant effect.

ISSN:0020-7543    

DOI:10.1080/00207549608904985

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This paper presents a method to generate 3-axis NC programs for rough milling processes, when the free-form surface is modelled parametrically by dual kriging. This general and powerful interpolation technique presents several advantages, since it includes piecewise linear and ‘spline’ interpolations as particular cases and least square methods as a limit case. The program for automatic generation of 3-axis NC G-code combines the flexibility of dual kriging modelling with a raster digitization of the solid volume delimitated by the surface to be machined. This volume is transformed into a 3-D mesh composed of blocks ‘to be deleted’ or ‘not to be deleted’. Tool paths are generated following the contour map approach and machining is performed from top to bottom for a sequence of horizontal cutting planes. At each level of planar machining, spiral or zigzag routines can be used depending on the length of the tool path. As the zigzag routine consists basically of scanning a digitized plane, in this paper we focus on the spiral routine based on a modification of the blind man's method originally proposed by Bao and Yim (1992). The modified algorithm produces spiral-in tool paths of a specified cutting width in order to avoid chattering which occurs during the machining of internal corners. The system was developed in C++ using object oriented philosophy. It is implementable on a standard micro-computer and the software is structured to offer a library of specialized machining functions for end-users. Two examples of free-form surfaces were machined on a CNC machine Matsuura MC-760 VX to demonstrate the practicability of the method.

ISSN:0020-7543    

DOI:10.1080/00207549608904986

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A heuristic is derived for real-time dynamic lot sizing at the bottleneck of a high volume manufacturer of many pan types. This bottleneck resource is subject to significant, random setup times. The problem is motivated by the scheduling requirements of a medical device manufacturing division of Johnson & Johnson, where meeting a common due date for all the current week's production is critical. The lot-sizing heuristic is one component of a hierarchical dispatching policy in which lot sequencing dominates lot sizing. A sample problem is developed and modelled as a dynamic program in order to demonstrate the form of an optimal solution. Numerical tests are provided which compare the dynamic program policy, a derived heuristic and other controllers. The results indicate the possibility of closed feedback control as an efficient method for dispatching pans. A prototype controller which was developed based on the heuristic control policy is briefly described.

ISSN:0020-7543    

DOI:10.1080/00207549608904987

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The problem of scheduling independent jobs on several serial workshops consisting of identical parallel machines is studied. Each job is processed by one machine in each workshop. This workshop environment is called a hybrid Flowshop. Each job has its own due-date and the objective is to minimize maximum tardiness or maximum completion time. Given that the problem is NP-hard, a set of list algorithms is developed to solve it. To evaluate the quality of these heuristics, lower bounds on the optimal solution have been derived and compared to the value of the heuristics on 1920 problems. Our results indicate that a heuristic based on Nawazet al. (1983) method outperformed the other approaches.

ISSN:0020-7543    

DOI:10.1080/00207549608904988

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

One of the control decisions in the operation of an automated guided vehicle (AGV) system is to determine the home locations of idle vehicles. In this paper, the problems of selecting home location of a vehicle when idle in a single loop AGV network is presented. As the number of unit loads to be picked up at each workstation dynamically changes over time, the optimum home location of vehicles may also change. Based on the objective of minimizing the expected response time of a vehicle, models are constructed. Example problems are given to illustrate the use of the solution algorithms. The results of the system response times obtained using the dynamic dwell point models are compared with those of other dwell point rules.

ISSN:0020-7543    

DOI:10.1080/00207549608904989

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor