• Journal of Korean Institute of Industrial Engineers
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• v.31 no.2
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• pp.135-142
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• 2005

This study addresses the problem of flexible technology acquisition in a multi-product market when demands are uncertain. We confine the concept of flexibility to the ability of manufacturing system to produce a number of different types of products, called a product-mix flexibility type. And an analytical model in which the economies of scope are incorporated explicitly as a feature of flexible technology is presented to find the optimal investment decision to acquire flexible technology and optimal production planning. The characteristics of optimal investment strategy related to capacity and production planning are discussed.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1553-1556
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• 1991

This paper deals with a problem on the selection of alternative tools in a flexible manufacturing system (FMS) where a lot of tools are required to produce a large variety of product items. An approach using branch and bound method is proposed to minimize a total number of tools required through the optimal use of the alternative tools. In this approach, tools are initially divided into tool subgroups based on graph theory for the purpose of the effective search of the optimal solution. A small example is also presented to highlight the effectiveness of the proposed approach.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.11a
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• pp.1-13
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• 1991

This paper describes two FMS, which were developed by SAEIL Heavy Industries. One is FMS for machining of circular parts, that are automobile's axle shafts. This system consists of 13 units, including 7 CNC machine tools. The other is FMS for machining of non-circular parts namely casted or steel block within size of 1.2 X 1.2 X 1.5m. This FMS consists of 8-machining centers, 1-automated warehouse, 2-unmanned Robo Trailers, and computer control room. All systems are functioning satisfactorily and so help greately towards automation of Korean industries.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.4
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• pp.75-86
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• 1998

We address the problem of determining the optimal processing times and pallet/fixture allocation in Flexible Manufacturing systems in order to minimize tool cost while meeting throughput targets of multiple part types. The problem is formulated as a nonlinear program superimposed on a closed queueing network of the FMSs under consideration. A numerical example reveals the potential of our approach for significant cost saving. We argue that our model can be Integrated Into the process planning system of an FMS to generate efficient process plans quickly.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.4
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• pp.7-22
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• 1991

This paper describes two FMS, which were developed by SAEIL Heavy Industries. One is FMS for machining of circular parts, that are automobile's axle shafts. This system consists of 13units, including 7CNC machine tools. The other is RMS for machining of non- circular parts namely casted or steel block within size of 1.2${\times}$1.2${\times}$1.5m. This FMS consists of 8-machining centers, 1-automated werehouse, 2,-unmanned Robo Trailers, and computer control room. All systems are functioning satisfactorily and so help greately towards automation of Korean industries.

• Journal of Korean Society for Quality Management
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• v.20 no.2
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• pp.118-128
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• 1992

The determination of appropriate buffer capacity is an important issue in the design of the advanced manufacturing systems and closely related to the system efficiency and flexibility. Work-in-process is usually not desirable. However, in reality, maintaining some capacity of buffer storage is inevitable in compensation for the machine blocking and break down. The objective of this paper is to present analytical methods and tools for the buffer capacity planning in the Flexible Manufacturing System Environments. The effects when machine blocking is critical factor are also discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.24
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• pp.97-103
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• 1991

This paper deals with a scheduling problem with the objective of maximizing the throughput rate in flexible manufacturing system with shop type. Manufacturing system is consisted of multi-stage in series. All kinds of parts are processed in same in processing time. No buffer space is allowed between stages, and no part waiting is allowed in each stage. Part flow control method for determining the optimal production sequence of all parts and the production starting time of each part is proposed.

• Industrial Engineering and Management Systems
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• v.15 no.1
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• pp.11-18
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• 2016

This paper considers a scheduling problem in a flexible job shop with a reconfigurable manufacturing cell. The flexible job shop has both operation and routing flexibilities, which can be represented in the form of a multiple process plan, i.e. each part can be processed through alternative operations, each of which can be processed on alternative machines. The scheduling problem has three decision variables: (a) selecting operation/machine pairs for each part; (b) sequencing of parts to be fed into the reconfigurable manufacturing cell; and (c) sequencing of the parts assigned to each machine. Due to the reconfigurable manufacturing cell's ability of adjusting the capacity, functionality and flexibility to the desired levels, the priority scheduling approach is proposed in which the three decisions are made at the same time by combining operation/machine selection rules, input sequencing rules and part sequencing rules. To show the performances of various rule combinations, simulation experiments were done on various instances generated randomly using the experiences of the manufacturing experts, and the results are reported for the objectives of minimizing makespan, mean flow time and mean tardiness, respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.1
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• pp.90-101
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• 1998

This paper presents a scheduling method that uses Petri net modeling and heuristic search to handle the tool setup. In manufacturing systems, a tool is attached to a particular machine to process a particular operation. The activity to attach a tool to a particular machine and detach the tool from the machine requires time. The processing time of operations varies according to the attached tool and the machine used. The method proposed in this paper uses Petri net to model these characteristics and applies a search algorithm to the reachability graph of the Petri net model to generate an optimal or near-optimal schedule. New heuristic functions are developed for efficient search. The experimental results that show the effectiveness of the proposed method are presented.

• Journal of the Korean Operations Research and Management Science Society
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• v.13 no.1
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• pp.57-57
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• 1988

This paper develops an adaptive scheduling policy for flexible manufacturing systems. The inductive learning methodology used for constructing this state-dependent scheduling policy provides and understanding of the relative importance of the various system parameters in determining the appropriate scheduling rule. Experimental studies indicated the superiority of the suggested approach over the alternative approach involving the repeated application of a single scheduling rule for randomly generated test problems as well as a real system, and under both stationary and nonstationary conditions. In particular, its relative performance improves further when there are frequent disruptions, and when disruptions are caused by the introduction of tiiight due date jobs, one of the most common surces of disruptions in most manufacturing systems.