摘要:

Curtailed sampling with one or two artificial ‘compressed limits’ (which are more severe than specification limits) are analysed for a single specification limit of a normally distributed variable, and the magnitude of the reduction in the sample size due to curtailment is evaluated. The computational methods for derivation of an efficient non-curtailed sampling plan are reviewed. A few curtailed sampling procedures are presented and numerical results are given.

ISSN:0020-7543    

DOI:10.1080/00207548508904752

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The purpose of this paper is to determine the cost effectiveness of recently proposed single-stage lot-sizing algorithms in multi-stage settings. Seven different algorithms and six comhinations of methods were examined in conjunction with four cost modification procedures. These procedures attempt to account for the interdependencies across stages by altering the costs employed for decision-making purposes. A series of simulation experiments was conducted where the set-up cost, the product structure, and the demand distribution were varied. It is concluded that the combination methods when used with some of the cost modifications result in enhanced performance in comparison to other sequential approaches.

ISSN:0020-7543    

DOI:10.1080/00207548508904753

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The productivity of manufacturing companies, and in particular their throughput efficiency, is very much influenced by the management procedures adopted for progressing orders from the point of receipt to delivery of the finished product. In some instances, the administrative system may unnecessarily lengthen delivery lead times. Thus, there is a case for defining and examining more closely the influence of order-handling systems upon productivity. Using case study examples, the paper describes a new approach to the analysis of order-processing systems. Possibilities for shortening delivery lead times are identified by examining company administrative procedures, producing diagrams of information and work flows within the organization. These may then be converted into lists of positive and negative influences upon throughput time. Alternative strategies for productivity improvement are evaluated according to their effect upon time consumption, through (a) the collapse of durations of those activities essential to order completion (termed ‘positive’ factors); and (b) the elimination of delays and excess slack (‘negative’ factors) to reduce idle time for individual orders. The conclusions presented concern the relevance of the study of order-handling systems to the identification of potential improvements in management productivity; the nature of the efficiency gains that may be made and the most appropriate methods of realizing the potential gains that exist in any individual system.

ISSN:0020-7543    

DOI:10.1080/00207548508904754

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

This paper describes a new method of evaluating relatively the performance of a task which is repeated many times, by using a work achievement quotient. The method is better than the usual analytical ways using the mean value or the standard deviation, because the performance is evaluated relatively in the interval [0, 1]. A development of the method which evaluates the work relatively and dynamically, using a tendency equation, is also discussed. These methods comprise the research and review system (RS) method. As an example of their application, the performances of three employees of an automobile company in repairing a fork-lift truck are compared.

ISSN:0020-7543    

DOI:10.1080/00207548508904755

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Recent developments in CAM and FMS require a computer-aided interface to connect product design and production planning to a manufacturing organisation which has been structured into mutually independent, cellular subsystems for flexible production. The paper provides some ideas and concepts for the planning, implementation and control of flexible production systems. These may be thought of as containing either flexible production cells or flexible manufacturing systems, A ‘flexible’ solution to the manufacturing organisation problem is a scheme in which the hospitality of cells towards product batches and the flexibility of jobs towards cells are maximised simultaneously. A changeover from FPCs to FMSs may constitute the ultimate goal of a modern organisation for manufacture.

ISSN:0020-7543    

DOI:10.1080/00207548508904756

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

This paper provides an heuristic for the planning and study of machine-component groups in flexible production cells and flexible manufacturing systems. The problem of group formation defined on master-component process routes is undertaken in terms of minimum differences between masters and maximum combinations of masters. Group formation is a ‘hard’ combinatorial problem subject to exponential growth of complexity as the number of decision-making variables increases. The heuristic is designed to search the solution space of the problem in monotone-increasing order of solution costs so as to avoid the enumeration of solutions for cost minimization.

ISSN:0020-7543    

DOI:10.1080/00207548508904757

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

An open-queueing network model with general service times and limited local buffers is developed to evaluate the performance of the flexible manufacturing system (FMS). The model accommodates two major characteristics of the FMS, namely, improving machine utilization and reducing work-in-process storage. A ‘flow equivalent’ decomposition approach is developed to derive approximate solutions to the model. Numerical examples are studied to illustrate the accuracy of the approximations.

ISSN:0020-7543    

DOI:10.1080/00207548508904758

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

This paper sets out, an approach to the job shop sequencing problem by determining the priority of a job from a linear combination of the basic quantities of operation times and due date. This achieves a simple yet unified format. Furthermore, since these basic quantities are used in fixed linear combinations in the majority of well-known simple heuristics, the rule outlined in the paper is capable of representing such heuristics as special cases within its framework. A performance function is used to assess the effectiveness of the rule andnolimitations are imposed on its structure. The form of the variable priority rule is then determined by a computer search routine basing its decisions on the values of the performance function. This overall approach to job shop sequencing we term the search sequencing rule (SSR).

ISSN:0020-7543    

DOI:10.1080/00207548508904759

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The design of assembly lines For mass production and, in particular, the task of assigning and balancing work elements between stations on an assembly line, has frequently relied upon the assumption that the problem conditions defined at the balancing stage will eventually become the operating conditions throughout the life of the assembly line. In many assembly line operations, especially those involving mixed-model or multi-model production, the acceptance of this assumption of continuity of problem conditions can lead to the introduction of assembly line designs that subsequently prove inefficient under actual operational conditions. The case therefore arises for an approach capable of examining this likely variation between the estimated balancing conditions and actual operating conditions (i.e. an approach to assessing assembly line versatility). Furthermore, there would be a distinct benefit when the examination of line versatility is undertaken at the assembly line design stage. Within this paper a simulation model, part of an integrated balancing and evaluation system capable of achieving this task, is described. Use of the simulation software is demonstrated by examples drawn from a test programme of over 200 simulations and summary conclusions are drawn from use of this simulation approach.

ISSN:0020-7543    

DOI:10.1080/00207548508904760

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

When designing a facility layout it is desirable to obtain an optimum design which satisfies certain necessary relationships among departments. Recent research has indicated that applying graph theory to the layout problem can result in the development of improved solutions, but little can be found to indicate how much better the resultant solutions are. The objectives of this paper are to develop a graph theory approach based on research experience and suggestions of Moore, Carrie and Seppanen, to develop a general computer program implementing the procedure and to compare its performance with that of CRAFT, CORELAP and ALDEP. The comparisons are based upon the adjacency relationships satisfied in the resultant layouts. The procedure finds the graph G equivalent to the problem being solved and then generates one of its maximal spanning trees, which after being transformed to its ‘string’ equivalent, is used to extract a maximal planar sub-graph of G. The dual of this sub-graph represents the desired solution. This approach allowed two usual problems to be avoided; firstly, testing for planarity of a graph and secondly, testing for cycles in the generation of a maximal spanning tree. The resultant PL/1 program, called graph and string-oriented layout (GASOL), is used to solve a standard set of eight problems, i.e. Nugent's problem set. The generated layouts were then compared to those obtained by CRAFT, CORELAP, and ALDEP on the same set of problems. The results of these comparisons showed that GASOL satisfies more of the number of layout adjacencies and achieves higher ‘scored’ layout arrangements than either CRAFT, CORELAP, or ALDEP, As a consequence more flow or material handling volume is included in a GASOL layout. The increase in the number of adjacencies ranges from a low of 53% to a high of 63.1%. This computational experience suggests that a graph theory approach to the layout problem can provide significantly improved results over those obtained by these existing computerized layout routines, with moderately increased computational times.

ISSN:0020-7543    

DOI:10.1080/00207548508904761

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor