• Journal of the Korean Society of Systems Engineering
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• v.2 no.1
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• pp.31-36
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• 2006

Development of launch vehicle needs a large-scale and complicated System Engineering discipline interfacing to small-quantity production with special manufacturing processes. In general, the System Engineering discipline of launch vehicle has its relationship with Production, Operations, Product Assurance and Management disciplines and its internal partitions into the functions of System Engineering Integration & Control, Requirements Engineering, Analysis, Design and Configuration and Verification. As a function of Product Assurance, reliability of launch vehicle plays an significant role in risk management, system safety, flight safety and launch certification through design assurance. Moreover, major functions of systems engineering are integrated by means of reliability in the phases of design and verification. Therefore, derailed identification of system engineering interfaces of reliability, and execution of tasks for reliability assurance is required for successful development of launch vehicle. This paper identifies specific pattern and mechanism of the interfaces between reliability and system engineering.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.22-33
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• 2018

Recently domestic manufacturing companies have been experiencing worsening profitability and stunted growth due to the long-term economic recession and the rapid rise of developing countries such as China and Southeast Asia. These difficulties force many companies to concentrate their core competencies on new value creation and innovation in order to gain momentum for new growth. Enterprise Resource Planning (ERP) has been considered as one of viable solutions. Among the various modules in ERP, shop floor control function in the production management module is rather limited. In order to overcome this problem, Manufacturing Execution System (MES) has been used as a subsystem which has a strong information gathering power and flexibility. Both systems interact closely with each other. In particular, ERP requires fast, accurate shop floor information at MES. This paper describes how to synchronize relevant information between ERP and MES with theory of constraints (TOC). The processing time information transmitted from the MES workplace is received at the ERP workplace. In the process, the received processing time is causing information distortion in ERP, when the information gathering standard of MES is different from the ERP information interpretation standard. The Drum-Buffer-Rope theory of TOC was applied to resolve this problem, therefore, information synchronization between both systems was made. As a precondition, the standard time of the upper ERP system was rearranged according to the capacity constraints resource. As a result, standard time restructuring has affected changes in labor costs. Standard labor costs have come close to actual ones, and information synchronization of MES transmission data has improved the reliability of standard product costs, such that it enabled various company-wide restructuring actions to be much more effective.

• 한국디지털정책학회:학술대회논문집
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• 2004.11a
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• pp.39-53
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• 2004

Data production systems are generally very large, distributed and complex systems used for creating advanced (mainly statistical) reports. Typically, data is gathered periodically and then subsequently aggregated and separated during numerous production steps. These production steps are arranged in a specific sequence (workflow or production chain), and can be located worldwide. Today, a need for improving and automating methods of supervision for data production systems has been recognized. Supervision in this context entails planning, monitoring and controlling data production. Two significant approaches are introduced here for improving this supervision. The first is a 'closely-coupledd' approach (meaning direct communication between production jobs and supervisory tool, informing the supervisory tod immediately about delays in production) - based upon traditional production planning methods typically used for manufacturing (goods) and adopted for working with data production. The second is a 'loosely-coupled' approach (meaning no direct communication between supervisory tool and production jobs is used) - having its origins in proven traditional project management. The supervisory tool just enquires continuously the progress of production. In both cases, dates, costs, resources, and system health information is made available to management. production operators and administrators to support a timely and smooth production of periodic data. Both approaches are theoretically described and compared. The main finding is that, both are useful, but in different cases. The main advantages of the closely coupled approach are the large production optimisation potential and a production overview in form of a job execution plan, whereas the loosely coupled method mainly supports unhindered job execution and offers a sophisticated production overview in form of a milestone schedule. Ideas for further research include investigation of other potential approaches and theoretical and practical comparison.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2038-2047
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• 2011

This paper presents a framework for production planning for a Slim MES(Manufacturing Execution System) of module operations in TFT-LCD(Thin Film Transistor-Liquid Crystal Display) production lines. There are differences in the line configurations and functions among the module operations in the TFT-LCD production systems. This paper presents the framework for the customized MES reflecting these differences. First, a production process is figured out through the analysis of the TFT-LCD module operations. Next, a mathematical modeling is presented reflecting the constraints of shop floors and an optimal schedule is presented through a case example. And a scheduling process using the dispatching rules reflecting the status of shop floors is presented and the performances are measured and compared. Finally, a design process for the Slim MES framework is presented.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.211-221
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• 2006

Manufacturing Execution System(MES) immediately enables users to share the information of systems industrywide, efficiently manages synthetic information with data collection through treating the data in a fast way, and helps their decision-making. MES for real-time information processing requires certain conditions such as data modeling of RFID, which has recently attracted attentions, and monitoring of each product unit from manufacture to sales. However, in the middle of processing the unit with a RFID tag, transponders(readers) can't often read the tag due to reader's malfunctions, intentional damages, loss and the circumstantial effects; for that reason, users are unable to confirm the location of the product unit. In this case, users cannot avoid tracing the path of units with uncertain clues. In this paper we suggest that the unique MES based on RFID and Bayesian Network can immediately track the product unit, and show how to evaluate it.

• The Journal of Information Systems
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• v.15 no.1
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• pp.169-189
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• 2006

Recently, many companies are trying to survive in a competitive business environment and they employ various kinds of information systems. Business Process Management (BPM) system is a software system that integrated enterprise information systems based on processes, which is considered an essential element for managing inner and outer processes. Though the BPM system has been applied to major processes only so far, companies begin to extends target processes applied into enterprise wide. In such settings, not only exact but also efficient management of processes is required. The efficiency of BPM has two perspectives: one is the performance of users that handle assigned tasks, and the other is the performance of the Business Process (BP) engine that carries out execution of processes. In this paper, in order to deal with the seconde perspective, we develop Drum, Buffer, and Rope (DBR) method, which have been considered innovative Theory of Constraint (TOC) method in manufacturing domain, for efficient management of processes. A new method, BP-DBR, has been developed, and we show that it is effective for business processes. The effectiveness of the method has been proved in terms of efficiency measures such as average process completion time and average number of completed processes, through a series of simulations on real banking processes.

• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.86-92
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• 2014

This paper provides an integrated view on human and system interaction in advanced and automated systems, which adopting computerized multi-functional artifacts and complicated organizations, such as nuclear power plants, chemical plants, steel and semi-conduct manufacturing system. As current systems have advanced with various automated equipments but human operators from various organizations are involved in the systems, system safety still remains uncertain. Especially, a human operator plays an important role at the time of critical conditions that can lead to catastrophic accidents. The knowledge on human error helps a risk manager as well as a designer to create and control a more credible system. Several human error theories were reviewed and adopted for forming the integrated perspective: gulf of execution and evaluation; risk homeostasis; the ironies of automation; trust in automation; design affordance; distributed cognition; situation awareness; and plan delegation theory. The integrated perspective embraces human error theories within three levels of human-system interactions such as affordance level, psychological logic level and trust level. This paper argued that risk management process should dealt with human errors by providing (1) reasoning improvement; (2) support to situation awareness of operators; and (3) continuous monitoring on harmonization of human system interaction. This approach may help people to understand risk of human-system interaction failure characteristics and their countermeasures.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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• pp.110-117
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• 2009

This paper introduces a case study for efficient generation of production schedules in a tube manufacturing system. The considered scheduling problem consists of two sub problems : lot sizing for a job and Job sequencing. Since these problems require simulation optimization in which the performance measures are obtained by simulation execution, the trade-off between solution quality and computation time is an important issue. In this study, the optimal lot size for every product type is determined from simulation experiments. Then, target production quantity for each product type is transformed to several jobs such that a Job consists of determined lot size. To obtain the good solution for a Job sequence in a reasonable time, a number of alternatives are generated from heuristic rules developed by intuition and analysis of the considered system, and a job sequence is selected from simulation experiments.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.194-200
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• 2021

This study proposes a plan to construct an integrated platform that reduces manufacturing costs and efficiently produce by integrating the systems of main producers, production subcontractors, and raw material subcontractors for the production of food packaging containers. The production plan of food packaging containers and raw materials is established in real time between the main producers, production subcontractors, and raw material subcontractors in consideration of the demand characteristics of each product. It establishes basic information that all processes from the production planning stage to the forwarding stage of the product are linked to each other. The progress of each producer of interlinked processes is shared in real-time to improve productivity and quality of food packaging containers and raw materials and reduce manufacturing costs. By monitoring the system of the main producer and the production subcontractor in real time, the production of food packaging containers is performed in a timely manner, thereby improving productivity. The application of the plan-do-check-action (PDCA) process, which includes planning, execution, evaluation and improvement in the production operation processes of the main producer, production subcontractor and raw material subcontractor, enables improved production compliance rate. The contents of the main producers, production subcontractors, and raw material subcontractors are managed in real time, then a converged production management system is established through the platform proposed in this study to ensure timely supply and demand of raw materials without delay in ordering.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.2
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• pp.92-99
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• 2007

Welding fabrication invariantly involves three district sequential steps: preparation, actual process execution and post-weld inspection. One of the major problems in automating these steps and developing autonomous welding systems, is the lack of proper sensing strategies. Conventionally, machine vision is used in robotic arc welding only for the correction of pre-taught welding paths in single pass. In this paper, novel presented, developed vision processing techniques are detailed, and their application in welding fabrication is covered. The software for joint tracking system is finally proposed.