摘要:

This paper focuses on studies where the goal is to optimize the key quality characteristics of a specific product or process. In order to do that, the process parameters must be adjusted in such a way that deviations from target are minimized while robustness to noise and to process parameter fluctuations are maximized. Since this is a multi-response, multi-objective problem, the optimum solution is a compromise. In this paper we present a gradient loss function which captures all the desired objectives, and propose a general methodology to perform the optimization analysis. This methodology is then carried out experimentally on a cosmetic product and the results are discussed.

ISSN:0020-7543    

DOI:10.1080/00207549508904871

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Deadlock problems of zone-control uni-directional automated guided vehicle (AGV) systems are discussed in this paper. Deadlocks of two types in such AGV systems are first classified from the perspective of shared resources, i.e. guide-path zones and buffers. A special class of Petri nets, attributed Petri nets (APN), is defined and used to represent the current state and to generate future states of zone-control AGV systems. We propose an algorithmic procedure to predict in real time and to avoid deadlocks that are caused by sharing guide-path zones in zone-control AGV systems. The proposed algorithm utilizes the current system state and future predicted states to avoid deadlocks. These states are obtained and generated from the obtained APN. A modular approach is employed to facilitate the construction of APN models of zone-control AGV systems.

ISSN:0020-7543    

DOI:10.1080/00207549508904872

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

One of the most important problems in designing a cellular manufacturing system is the formation of machine cells and the grouping of parts. Most of the existing cell design procedures operate on a binary part-machine incidence matrix to identify block diagonality. Important factors such as part operation sequence and demand volume have not been commonly considered in past research. In this paper, a sequence-based materials flow procedure is developed to solve the cell formation problem. The new cell formation procedure is designed to consider operation sequences in accurately determining the costs of inter-cell movement, as well as forward and backward intra-cell movements. Extensive comparisons of the new cell formation procedure with the relevant existing procedures in the literature demonstrate the effectiveness of the new procedure.

ISSN:0020-7543    

DOI:10.1080/00207549508904873

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This paper deals with on-line scheduling in a multi-cell flexible manufacturing system, operating in a produce-to-order environment. A two level distributed production control system (DPCS) is developed and tested through a simulation study. The DPCS allows autonomous and simultaneous operation of each cell-controller, utilizing only local and short term information as well as simple heuristic rules. Simulation experiments show that the proposed DPCS achieves good results in throughput, tardiness of orders and WIP inventory level and that it is robust to machine and handling device failures.

ISSN:0020-7543    

DOI:10.1080/00207549508904874

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A system simulation method for economic raw material selection is presented, based on a realistic example. The total cost considered in raw materials selection is deemed to include the basic raw material cost, the extra manufacturing cost due to the selection of the particular raw material, and the final product quality cost. These costs are systematically simulated for three typical areas of interest: for the purchasing operation, for the manufacturing process and for the final product quality acceptance by the customer.

ISSN:0020-7543    

DOI:10.1080/00207549508904875

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This paper develops and describes a systematic computer-assisted methodology for the selection of material handling equipment (MHE). A microcomputer based system called ADVISOR models the material handling equipment selection process and employs information on 77 of the most common equipment types used in material transport, positioning, unit formation, and storage. The system identifies the appropriate equipment type for an application in two stages. At the primary stage, potential equipment types are identified through the use of physical requirements of the material handling activities specified by users. Eligible equipment are ranked according to their normalized accumulated rating and placed in a candidate equipment list. After this, a second stage involving an economic analysis for each eligible equipment is performed. The evaluation criteria provided by ADVISOR include present worth (PW).equivalent uniform annual cost (EUAC), return on investment (ROI), and payback period(PP) methods. Through ADVISOR, the expert-like MHE selection system recommends a ranked set of equipment based on user input data. An example problem is given in the paper to demonstrate the use of the system.

ISSN:0020-7543    

DOI:10.1080/00207549508904876

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

We consider the problem of scheduling storage and retrieval orders under dual-command operations in a unit-load automated storage/retrieval system. The objective is to minimize the weighted sum of earliness and tardiness penalties about a common due date. We propose four heuristics based upon a two-step approach where dual-command cycles are formed first and then optimally scheduled. A mixed-integer programming model is also formulated to obtain an optimal solution. Performances of the heuristics are compared in the simulation tests. Computational results show that some heuristics perform favourably.

ISSN:0020-7543    

DOI:10.1080/00207549508904877

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In managing the situational factors to improve the performances of production and inventory control systems, the sequence for managing the factors should not be arbitrarily decided, since the factors are not independent but are inter-related. To determine the suitable sequence, the inter-relationships among the situational factors are studied. Based on these relationships, a hierarchy of the factors is obtained by using Fuzzy Interpretative Structural Modelling (FISM). In addition, indirect relationships between the factors are also studied. Based on their driver power and dependence, the factors are classified into sectors. The approach presented can be used as a guideline for determining the sequence for managing the situational factors.

ISSN:0020-7543    

DOI:10.1080/00207549508904878

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A features-driven knowledge-based approach to the quantitative assessment of castings for ease of manufacture is presented. Geometric features such as undercuts, holes, sharp corners and hot spots are recognized from a solid model of the casting and analysed by a number of dimensionless criteria functions. The criteria have been developed through a detailed study of design heuristics used by practising engineers and are written as functions of geometric attributes of component and tool features. This is useful for identifying problem features in a casting at an early stage and for objective comparison of two or more design solutions for manufacturability. The proposed approach lends itself to computer implementation for automating the design of castings in a concurrent engineering environment.

ISSN:0020-7543    

DOI:10.1080/00207549508904879

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Due to increases in versatility and the complexity of demands in modern manufacturing systems a growing need has evolved t0 simplify the control of these systems while maintaining a high degree of efficiency and flexibility in operation. The segmented flow approach (SFT) suggested in this paper is a possible solution to these needs. This structure simplifies the control task by reducing the need for dispatching and by eliminating the need for routeing material handling devices and scheduling traffic at intersections. Each task involves only one material handling device and one possible route. This structure maintains a high degree of efficiency by operating material handling devices in a bidirectional mode and eliminates congestion and blocking by operating them on mutually exclusive tracks. This paper introduces a design procedure for an SFT implemented system using a minimum cost objective, and compares the throughput and time in system performance of this system to a conventional system and a tandem type system by means of simulation.

ISSN:0020-7543    

DOI:10.1080/00207549508904880

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor