摘要:

The purpose of this study is to determine if the selection of the distribution used to describe processing times in JIT simulations will affect the simulation results. Three distributions that closely adhere to the requirements for describing processing times in the JIT environment are identified, namely the truncated normal, the gamma, and the log-normal distributions. The results indicate that no significant difference in performance could be attributed to the choice of the distribution, i.e. as long as the distribution selected fits closely with the requirements for describing processing times in the JIT environment, the results of the simulation study will not be affected. The gamma distribution is recommended since it specifically meets the requirements for describing processing times in the JIT environment and is computationally efficient.

ISSN:0020-7543    

DOI:10.1080/00207549208942874

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The design and implementation of flexible machining installations calls for a high investment in capital and manpower. A review of the state of the art of tools to model such facilities is presented first in order to establish the merits of different approaches. Emphasis is then placed on describing a knowledge based approach which is capable of modelling alternative facilities over multiple levels of detail. Finally an application example utilizing the approach is presented with illustrations of typical results.

ISSN:0020-7543    

DOI:10.1080/00207549208942875

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The problem of sequencing mixed model assembly lines is characterized by a set of parameters whose values are dictated by the actual manufacturing environment. In some cases, it may be desirable to minimize the size of the facility, while in others, the throughput time is paramount. Important design considerations include operator schedules, the product mix, station boundaries, and the launching discipline. The intent of this paper is to present a common mathematical framework in which each possible variant can be addressed. By implication, a solution technique developed for one can be readily adopted for the others.

ISSN:0020-7543    

DOI:10.1080/00207549208942876

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A statistical model is established to estimate the effects of the geometric and nongeometric errors on the quality of the operation for various operating speeds. Furthermore, a stochasitc optimization problem is formulated to obtain the optimal operating speed for a given accuracy in the robotic operations. To demonstrate this approach, the experiments on a PUMA 560 robot are used as an example.

ISSN:0020-7543    

DOI:10.1080/00207549208942877

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This paper describes a procedure that can be used by facility designers to allocate space to manufacturing cells. The procedure takes into consideration the area and shape requirements of individual cells as well as any occupied regions on a floor plan. A layout is represented as a collection of rectangular partitions organized as a slicing tree. The solution method involves searching through the space of all slicing trees of a given structure. An effective simulated annealing algorithm capable of minimizing inter-cell traffic flow and enforcing geometric constraints is presented. The algorithm is compared with two local search methods with encouraging results.

ISSN:0020-7543    

DOI:10.1080/00207549208942878

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In this note we analyse the dynamic design problem for automated manufacturing systems involving a unidirectional closed loop material handling system with one load/unload station by means of simulation. The experimental conditions and layout strategies employed are the same as those used in an earlier study where each processing centre had input/output capability. When compared to findings in earlier research, material handling requirements increased by as much as 200 % due to the single load/unload station versus having such capability at each processing centre.

ISSN:0020-7543    

DOI:10.1080/00207549208942879

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A new method (Computerized LAyout Solutions using Simulated annealing —CLASS) that considers the inter-cell and intra-cell layout problems in a cellular manufacturing environment is presented. It addresses the relative placement of equidimensional manufacturing entities within a discrete solution space in an attempt to minimize the total material flow (cost) between these entities. An approach to accommodate the relative sizes of the entities is also presented. The method is based on simulated annealing, which has been successfully applied for the solution of combinatorial problems. A major advantage of this technique is the insensitivity of the final solution to the initial conditions. In addition, some important practical issues such as intra-cell layout of machines in predetermined configurations (e.g., row-wise or circular arrangements), have been addressed. Several comparisons were made with some of the existing approaches for facility layout, such as CRAFT, HC63-66, etc., that yielded results of equal or better quality for each of eight classical test problems.

ISSN:0020-7543    

DOI:10.1080/00207549208942880

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A two step analysis was performed to solve the tool path optimization problem. A computer program was initially created to estimate the tool path as a function of the orientation of cut. An analysis was performed using this program and graphical plots were obtained on different convex polygonal shapes. It was inferred from these plots that an optimization was possible. A detailed analytical model was hence created that allowed the nature of the relationship between the variables to be studied. This analytical function related the total path to orientation as an arithmetic progression of trigonometric functions based purely on object geometry and cutter diameter. The transformation orientations provided the optimal tool paths. The global minima of the length of cut function was obtained by orienting the cutter parallel to the longest edge. The present algorithm can be extended to include generic prismatic shapes in the future. Therefore the feasibility of analytical modelling as well as the results of tool path optimization are well verified.

ISSN:0020-7543    

DOI:10.1080/00207549208942881

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In a recent paper, Christy and Kanet (1990) examined the performance of several dispatching rules in a forbidden early shipment environment. Their primary performance measure was time-weighted inventory value. This study re-examines their results using a new model, with a net present value (NPV) performance measure. The results show that using NPV and inventory objectives lead to different scheduling decisions. Also examined are the reasons for relatively poor performance of operation-based due date rules.

ISSN:0020-7543    

DOI:10.1080/00207549208942882

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The success of a just-in-time (JIT) implementation effort is dependent, partially, upon the availability of simulation and modelling tools that are both easy to use and adaptable for modelling real-world systems. During JIT implementation, some subsystems will continue to retain their ‘push’ characteristics. Thus, an effective simulation software language must offer the flexibility to model JIT elements, while preserving the traditional features for modelling push elements. We propose a control paradigm for implementing the ‘pull’ control structure of JIT systems. The paradigm is based upon the concept of ‘kanban satisfaction’ which is used to provide the control structure which permits the pulling of material to take place. The concepts are extended to describe the modelling requirements for interfacing JIT modules with traditional push systems.

ISSN:0020-7543    

DOI:10.1080/00207549208942883

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor