摘要:

A simulation model of an actual job shop was used to compare group technology with traditional job shop manufacturing. The experiment compared shops which had four different layouts, designed to emphasize different features of traditional job shops and group technology shops, and four distributions of demand for end items. The group technology shops exhibited superior performance in terms of average move time and average set-up time. The traditional job shops had superior performance in queue related variables (average queue length, average waiting time, work-in-process inventory, etc.). This was caused by group technology's dedication of machines. The effects of the queue related variables outweighed the effects of average move time and average set-up time: the average flow time was shorter in the traditional job shop than in the group technology shops.

ISSN:0020-7543    

DOI:10.1080/00207548608919795

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The present investigation presents a discussion of two methods used to define a datum line with respect to which the error of straightness is calculated, namely the least squares line method and the end points line method. The paper investigates uncertainties of both methods. Adopting statistical accuracy, the analysis of experimental data using the two methods demonstrated that both methods give almost the same value of error of straightness of the surface under test with the same uncertainty. Nevertheless, for practical application the end point line method is more favourable for not only does it offer a suitable mathematically defined datum but also it is simple, straightforward and independent of personal judgement.

ISSN:0020-7543    

DOI:10.1080/00207548608919796

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A two level heuristic for the resource constrained scheduling problem is presented. This heuristic is based on a combination of priority rules where utilization of resources by the operations, the critical path of operations in a job, and the due dates of the jobs are taken into account. The schedules that this heuristic generates have been compared with small problems for which optimal solutions are available and it is shown that these solutions are generally within 15% of the optimal. Also the polynomial time and space complexity of the heuristic is demonstrated.

ISSN:0020-7543    

DOI:10.1080/00207548608919797

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

This paper is an extension of the well known rank order clustering algorithm for group technology problems. The ROC method is analysed and its main drawbacks are identified. The present method uses the ROC algorithm in conjunction with a block and slice method for obtaining a set of intersecting machine cells and non-intersecting part families. Then a hierarchical clustering method is applied based on a measure of association among pairs of machine cells. Clustering is terminated when all the surviving cells are non-intersecting or when a single group is formed. In the latter case, the number of cells is determined on the basis of a suitable decision criterion and the bottleneck machines are identified at the appropriate hierarchical level in the clustering process.

ISSN:0020-7543    

DOI:10.1080/00207548608919798

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Computationally efficient analyses are presented which provide rapid decisions making capabilities for determining whether various types of planned motions may be successfully executed. Algorithms are based upon a geometrical quantification of the manipulator dexterity and workspace, and as far as the authors are aware these algorithms are new. They enable the determination of possible motions during the task planning stage without requiring the computation of individual joint angles which produce the desired end-effector trajectory. This paper investigates essentially rectilinear motion using by way of example, a planar 3R manipulator which provides a proper analytical foundation for extension to various types of spatial manipulators.

ISSN:0020-7543    

DOI:10.1080/00207548608919799

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

This paper deals with two important decisions in a two-echelon inventory system operating under stochastic demand and stochastic leadtime. The first of these decisions is the aggregate level of safety stock carried in the system, The second decision is the allocation of the total safety stock within the system. A simulation is performed to study the sensitivity of the system to both decisions. Based on the study, guidelines for efficient management of safety stocks in a two-echelon inventory system are suggested.

ISSN:0020-7543    

DOI:10.1080/00207548608919800

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

It has been suggested that the efficiency and economics of a flexible manufacturing system can be improved through judicious grouping of machines and parts. This paper addresses the formulation of families of parts requiring similar manufacturing with closely related machines using the topological concepts of polyhedral dynamics (i.e.q-analysis).

ISSN:0020-7543    

DOI:10.1080/00207548608919801

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A work-force planning model is developed for minimizing the costs of standard wages, over-time wages, hiring and firing. The optimal work-force size and hiring/firing plan are found by plotting a labour requirement curve and calculating the change in cost due to infinitesimal changes in work-force size. Simple optimality criteria are derived by determining when the change in cost equals zero. Based on the model's assumptions, the following planning principles are identified: (1) Over-time and under-time should only be used during periods when the work-force size is not changing. (2) If work-force size is kept constant, the proportion of time in which over-time is used should equal 1/P, wherePis the ratio of the over-time wage rate to the standard wage rate. (3) Cost changes gradually when the work-force size is either made larger or smaller than the optimum. Therefore, a wide range of work-force sizes yields costs that are close to the optimum.

ISSN:0020-7543    

DOI:10.1080/00207548608919802

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A construction algorithm for the plant layout problem is presented. The problem is formulated as a generalized assignment problem with the objective of minimizing total movement costs. The solution algorithm is a heuristic that utilizes an analogy to the special case of locating one item within a warehouse repetitively for placing and constructing departments. The procedure is sensitive to the departmental areas and approaches the problem as one of area placement. The algorithm provides a large degree of regularity in departmental shape and overall layout outline without having to pre-specify any particular shape. The compact and simple computational nature of the algorithm makes it suitable for adaption to an interactive microcomputer environment.

ISSN:0020-7543    

DOI:10.1080/00207548608919803

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor