摘要:

The initial stage in the facilities design of cellular manufacturing systems involves the identification of part families and machine groups and forming cells possessing specific manufacturing capabilities. A new heuristic for the part family/machine group formation (PF/MGF) problem is presented in this paper. The distinguishing feature of this heuristic is its consideration of several practical criteria such as within-cell machine utilization, work load fractions, maximum number of machines that are assigned to a cell, and the percentage of operations of parts completed within a single cell. Computational results, based on several examples from the literature, show that this heuristic performs well with respect to more than one criteria. The heuristic also clarifies the source of various arguments in the literature concerning the ‘goodness’ of the solutions obtained by other researchers. An application of the heuristic to a large sample of industrial data involving 45 workcentres composed of 64 machines, and 305 parts is given, and the usefulness of the heuristic for trading-off several objectives is illustrated.

ISSN:0020-7543    

DOI:10.1080/00207548708919868

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

An important factor in the design of automated guided vehicle systems (AGVS) is the flow path design. This paper presents an approach to determining the optimal flow path. The objective is to find the flow path which will minimize total travel of loaded vehicles. The problem is formulated as a zero-one integer program. Examples are presented to demonstrate the approach.

ISSN:0020-7543    

DOI:10.1080/00207548708919869

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In this paper a heuristic procedure is developed for solving the problem of planning machine replacements for a serially dependent production system. Given a finite planning horizon, the decision-maker wishes to decide (1) which periods, if any, that the entire production system must be shut down in order to make replacements, and (2) what specific machine or machines in the system should be scheduled for replacement during each of these downtime periods. The problem involves a balancing of costs. If the production system is brought down to make one or more replacements a fixed downtime cost is incurred; this cost is independent of the machines replaced during the downtime. In addition, other fixed coats are incurred for each of the machines replaced. Our motivation for scheduling these replacements is to realize lower variable costs for operating the machines. The variable operating costs are assumed to increase as the age or vintage of the machines increases. An optimal replacement policy is one in which the total of the present-value fixed and operating costs are minimized for the entire planning horizon. The paper also presents computational results using the heuristic to solve a large number of randomly generated test problems of varying numbers of machines and periods. These heuristic solutions are compared to known optimal solutions for a number of the problems. One of the important advantages of the heuristic procedure is that it is capable of producing several solutions to a given problem, all rank ordered by increasing cost. Thus, the decision-maker is afforded alternative choices from which he or she may select a replacement policy.

ISSN:0020-7543    

DOI:10.1080/00207548708919870

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Numerous articles suggest using the Japanese manufacturing strategy of minimizing inventories by producing small lot sizes. However, few studies actually have investigated the relative advantages or disadvantages of such a strategy. Worker productivity improvements during production of a batch (learning)and the loss of productivity improvements due to the breaks between batches (forgetting)both influence the optimal lot size for a product. The results of this study indicate that worker forgetting in a batch production environment can substantially increase optimal lot sizes. Since forgetting causes a type of setup cost by penalizing breaks in production, it is intuitive to expect an increase in optimal lot size for forgetting. This study confirms the expectation. What is interesting, however, is that only a small amount of forgetting is required to substantially increase the optimal lot size. The conditions under which lot sizes need to be significantly increased are discussed and illustrated. The results also suggest that special attention must be given to eliminate forgetting due to production disruption when using just-in-time scheduling techniques to reduce lot sizes. The use of automated processes in batch production may overcome the need for large lot sizes by negating the worker forgetting cost, which is a form of setup cost. Robotic technologies or flexible manufacturing systems are types of automated processes which can diminish the forgetting effect in a batch production mode, and therefore, allow efficient production of small lot sizes.

ISSN:0020-7543    

DOI:10.1080/00207548708919871

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The concept of CIM and FMS has created a whole new area of what is called ‘tool management system’ (TMS). For efficient operation of TMS, a real-time monitoring of tool condition is desirable. Tool health monitoring is critical in today's automated production and is likely to become crucial as we progress towards the unmanned factory of the future. The paper describes the development of a microcomputer-based acoustic emission (AE) system for monitoring progressive wear of a cutting too!. It also includes results of experiments conducted with the system. The state-of-the-art in AE technique and its comparison with other techniques for tool condition monitoring are also presented.

ISSN:0020-7543    

DOI:10.1080/00207548708919872

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This paper investigates the development of a production control strategy for a custom door manufacturer. A Kanban system is developed for the production environment. Simulation and discrete optimization techniques are applied to configure the system. The paper demonstrates that a Kanban approach can be applied to a production environment which neither represents a pure flow shop nor contains balanced production processes. It also highlights the difficulties that can arise in performing a discrete optimization upon conflicting multiple stochastic responses.

ISSN:0020-7543    

DOI:10.1080/00207548708919873

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The flute shape to produce two new drill configurations are presented. The first configuration is to provide a straight diametral lip which could be extended to eliminate the chisel edge. The second configuration, which encompasses the feature of the first one at the inner portion of the lip and the curved shape at the outer portion of the drill lip, is provided to enhance the overall life of the drill.

ISSN:0020-7543    

DOI:10.1080/00207548708919874

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The problem of scheduling parallel processors in a make-to-stock environment with sequence setup costs is considered. A new algorithm which formulates a series of 0-1 integer sub problems is proposed and contrasted with an earlier formulation (Dearing and Henderson 1982,1984). Parallels between the sub problem formulations and generalized networks are discussed. The efficiency and quality of the solutions provided were tested using previously published data for a loom assignment problem. The heuristic solution was evaluated against the optimal integer linear programming (ILP) solution, and a rounded linear program (LP) approximation to the optimal solution for several sample problems. Results indicate that the heuristic is efficient, provides near optimal solutions to production planning problems and requires significantly less computing capability than previously reported LP, TLP approaches.

ISSN:0020-7543    

DOI:10.1080/00207548708919875

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Absenteeism is one of the major problems of Indian industries. It necessitates the employment of more manpower than the jobs require, resulting in the increase of manpower costs, and lowers the efficiency of plant operation through lowered performance and higher rejects. It also causes machine idleness, if extra manpower is not hired, resulting in disrupted work schedules and assignments. Several studies have investigated the causes of absenteeism (Vaid 1967) for example and their remedy and relationship between absenteeism and turnover with a suggested model for diagnosis and treatment (Hawk 1976) However, the production foremen and supervisor will face the operating task of determining how many extra operatives are to be hired in order to stave off the adverse effects of absenteeism on the man-machine system. This paper deals with a class of reserve manpower models based on the reject allowance model familiar in quality control literature. The present study considers, in addition to absenteeism, machine failures and the graded nature of manpower met within production systems and seeks to find optimal reserve manpower through computer simulation.

ISSN:0020-7543    

DOI:10.1080/00207548708919876

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor