• 산업경영시스템학회지
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• 제27권2호
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• pp.17-23
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• 2004

Changes in manufacturing system are those that occur during production and cause the systems to behave unpredictably. So scheduling problem in this dynamic Industrial environments is very complex. The main concept of this dissertation is to continuously monitor a manufacturing system status(Rate of Prior Job, Rate of Large Job, Rate of Shortest due date Job, Job Interval Time) and detect or predict a change so that scheduling system will react by modifying production schedule(dispaching rule) to lessen the effects of this change.

• 한국정밀공학회지
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• 제9권4호
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• pp.36-43
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• 1992

This paper presents a hierarchical real-time operation control and monitoring scheme of the FMS/CIM center which has been implemented at the Automation and Systems Research Institute of Seoul National University. The hierarchical structure of the whole scheme consists of three lavers. The upper layer is in charge of on-line scheduling, computer network control, shop-floor monitoring and command generation for AGV dispatching, machining, assembly, inspection, set-up, etc. The middle layer has six modules, which are installed in the FMS host computer with the upper layer and run on the multi-tasking basis. Each module is connected to one of six cell controllers distributed in the FMS model plant and transfers operation command down to each cell controller through the Ethernet/TCP-IP local area network. The lower layer is comprised of six cell control software modules for machining cell, assembly cell, inspection cell, set-up stations. AS/RS and AGV. Each cell controller reports the status of the manufacturing facilites to the middle layer as well as ecxecuting the appropriate sequence control of the manufacturing processes.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2007년도 춘계학술대회
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• pp.73-80
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• 2007

Recently, the strategy of the age of limitless competition for existence of manufacturing company appears for the enhancement of productivity through the automatic system, the reduction for the cost for standardization and the decision making process for the information system. Especially the critical success factors in manufacturing company can be summarized for the establishment of production visibility through the production management, material & work-in-process management, the establish of the flexible manufacturing system for the changed order priority and the establish of the quality system for improvement of product and process quality. The existing production management systems supply only simple information about production results on real time, can delay quick decision making. And it can prevent acquiring the information about various customer needs and the communication problems with other systems. In this paper, it will show MES system, a solution for the problems of existing production management systems. And through a case study of D company, it will reveal improvement effect on shipment error using MES system and economic analysis for MES itself.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1996년도 춘계학술대회
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• pp.15-15
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• 1996

A shop floor control system (SFCS) is the central part of a CIM system used to control the activities of several pieces of manufacturing equipment (e.g., NC machines, robots, conveyors, AGVs, AS/RS). The SFCS receives orders and related process plans, and then performs selecting a specific process routing, allocating resources, scheduling the workpieces, downloading the processing instructions (e.g., RS-274 instructions for NC machines, VAL II programs for robot), monitoring the progress of activities, detecting and recovering from errors, and preparing reports on the status of the manufacturing system. Simulation has been utilized in discovering control policies used for resolving shop floor be control problems such as resource contentions, part dispatching, deadlock. The simulation model must be designed to respond to real-time data coming from a shop floor. However, to rapidly build a realtime simulation model of SFCS cannot be easily accomplished. This talk is to address an automatic program generator of discrete event simulation model for shop floor control from process plans and resource models. The program generator is capable of constructing complete discrete simulation models for multi-product and multi-stage flexible manufacturing systems.

• 한국정밀공학회지
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• 제14권2호
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• pp.84-91
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• 1997

This paper reports the effort for developing this new Unified Manufacturing Instruction Set and its environment, called here UniSet, to deal with difficulties in set up and operation of Flexible Manufacturing Cells, UniSet has been developed as a non-exclusive unified manufacturing instruction set based on com- parisons of the prevailing machine tool and programming primitives. UniSet allows programmers to deal with only one instruction set, if they so desire, in a single coherent enviroment, rather than numerous machine programming languges. The software system is coded in an Object-Oriented Programming (OOP) language, Smalltalk, and derives its paradigm from the OO philosophy. Test results are also includ- ed to demonstrate the applicability of the approach employed.

• 산업경영시스템학회지
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• 제18권33호
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• pp.63-70
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• 1995

Most of small-to-medium sized companies use computer to manage and control their manufacturing system. However, it is real hard to find a company which uses the system properly. There are several reasons. First of all, appropriate software to satisfy user's needs is not available and there is lack of mind to computerize. Therefore, this paper focuses to show difficulties which they will encounter, develop a model of computerized production management system and define proper level of computerization. An experimental system has been developed for an auto-parts manufacturing company using IBM-PC in the environment of MS-DOS and CA-Clipper.

• 한국정밀공학회지
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• 제12권4호
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• pp.88-99
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• 1995

The demand for automatic manufacturing systems is increasing. Flexible Manufacturing System(FMS) is usually considered as a soluting for the shop floor automation. One of the difficulties in FMS is the communications problem. Since various machineries with different communications protocoles are included, applying a unified scheme is almost impossible. Therefore, a systematic approach is a key point to solve the communication problem. A cell is difined as an automation unit where closely related for a job reside together. A cell is a messenger between upper level computers and lower level machine equipment. In this research, the fonctions of the cell are defined to have more capabilities than conventional cells since a cell can be often a total manufacturing system is a small to medium sized factory. The cell conducts communications with different machines through the communications schemes established here. A set of software system has been developed according to the defined communication. The software has been tested for a simulation and real experiments for proof.

• 한국정밀공학회지
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• 제14권1호
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• pp.108-118
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• 1997

The heterarchical structure provides a more attractive solution to the conventional hierarchical structure as the density and level of distrubution of computing resources in manufacturing system expands. Tracing the evolution of control structures for automated manufacturing systems, this paper discusses the design principles for heterarchical system to reduce complexity, increase extendability, flexible configurability and suggests a good example of real-time adaptation using the concept of intelligent agent of manufac- turing entities and fault diagmosis system.

• 한국의류학회지
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• 제21권1호
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• pp.19-34
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• 1997

The goals of this study are to suggest the guidance for automated clothing manufacture by analysis the technology of the automated manufacturing facilities and to propose how improve the efficiency of the production planning and management for automated clothing manufacture In this study, the research about the automated clothing manufacturing machines and the analysis about the modules and functions of apparel information systems were performed. In order to understand the factory automation of the larger clothing firms, the case study method was used. The case study samples were 3 clothing firms. The results and suggestions are as follows: 1. An information technology for automated clothing manufacture has enabled the computer integrated manufacturing system to connect production planning and management part with each work station on the factory floor. 2. The apparel information system to integrate and manage manufacturing informations from each workstation and the apparel CAD system are used in the department of production planning. At the cutting room, there are automated manufacturing machines like an automatic spreading system and an automatic cutting system. Sewing room has the computer controlled unit production system and semi-automated sewing machines. In addition, in the finishing room, an automatic packing machine and a press system are used and besides a warehousing system has been developed. Considering these available technology, for better product efficiency, it is necessary to consider and utilize the specific character of these automatic manufacturing machines and computer system whether they proper to each product style. 3. Most of the clothing manufacturers are in the stage of semi-automated manufacture. In order to improve the manufacturing environment, it is needed to gradual procedure of manufacturing automation with considering the firm's financial condition, existing facilities and staffs operating machines. The case study sample firms are in the high degree of manufacturing automation. They can accomplish the flexible manufacturing system to link the information system with each work station menufacturing system by computerized control. For the case of the firm having already used the computer integrated manufacturing and managing system, it is necessary that the function to deal with drawing information is added to the retaining module of the apparel system.

• 한국통신학회논문지
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• 제19권10호
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• pp.1935-1944
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• 1994

FMS(Flexible Manufacturing System)는 로봇, 수치제어기기 등의 프로그램이 가능한 생산설비 하드웨어로 구성된 분산시스템이다. FMS의 효과적인 운용을 위해서는 생산설비 하드웨어를 통합 제어하기 위한 소프트웨어의 존재가 필수적이다. 그런데 FMS의 복잡성과 다양한 변화가능성은 통합제어 소프트웨어의 구축 및 유지, 보수를 어렵게 한다. 이를 해결하기 위하여 본 논문에서는 객체지향 FMS 통합제어 모델을 제안한다. 제안된 모델에서는 FMS에 실재하는 셀이 가상 셀 객체로 모델되어, 통합제어를 위하여 필요한 데이터와 연산들이 캡슐화되어 객체지향 데이타베이스에 관리된다. 또한 이 밖의 FMS운용을 위해 필수적인 데이타와 이들간의 관계성도 데이타베이스에 관리된다. 본 논문은 제안된 모델을 기반으로 구현한 통합제어 소프트웨어시스템인 FREE(Fms Run Time Executive Environment)를 바탕으로 통합제어 데이타베이스에 대하여 기술한다.