• IE interfaces
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• v.14 no.4
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• pp.341-347
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• 2001

This paper describes a real-time manufacturing scheduling system on Internet using DBR(Drum-Buffer-Rope) scheduling method. We intend to change company-oriented manufacturing scheduling, which has been used at most manufacturing companies, to customer-oriented manufacturing scheduling. Customers can not only choose product kinds, quantities and order due dates, but also evaluate optimum order due date by themselves in real-time through internet and then the results will be converted into practical manufacturing scheduling. If the company cannot meet the customer order due date, it will offer reliable and accurate information to the customers by suggesting the earliest order due date. To evaluate the customer order due date in real time, companies should be able to estimate their accurate production capacity. This research uses Goldratt's DBR scheduling method to realize that function. The DBR scheduling does not recognize the production capacity of the whole company, but only of the constraint resources which have a great effect on the company throughput. Thus, it can improve the customer service level as well as the profit by performing more dynamic and reliable scheduling through Internet.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2935-2944
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• 2009

This paper proposes Dual DBR(Drum-Buffer-Rope) system for a small-to-medium-sized PCB(Printed Circuit Board) manufacturing line. DBR method of TOC(Theory of Constraints) is an effective system for a small-to-medium-sized company to build production scheduling system. But to apply it to PCB line, it needs more technical consideration because of multiple constraints, looping process line and complex buffer management. This paper proposes an answer of these problems using Dual DBR to build production scheduling system more successfully. And it was confirmed that lead time was reduced more than 20% applying Dual DBR system to a domestic PCB manufacturing line actually.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.59
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• pp.21-36
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• 2000

The drum-buffer-rope(DBR) system is a finite scheduling mechanism that balances the flow of the production system. DBR controls the flow of materials through the plant in order to produce products in accordance with market demand, with a minimum of manufacturing lead time, inventory, and operating expenses. This paper integrates the best of MRP push system and JIT pull system with DBR system, efficiently adapts these logics to capacity constraint resources, and contributes to the evolution of synchronous manufacturing. The purpose of this paper is, thus, threefold. The first objective is to identify the frame of theory of constraints(TOC) and the logic of DBR scheduling. The second objective is to formulate the DBR constraint scheduling problems(DBRCSP) in a job shop environments. Finally, the paper is to suggest the solution procedure of DBRCSP for embedding TOC into MRP/JIT along with an numerical expression. In addition, illustrative numerical example is given.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.31-36
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• 2006

Most production scheduling system in the ERP is based on the MRP. The MRP does not adapt to the change of the product design and the production schedule. It is important to keep due date in make-to-order production small and medium company. But it hard to keep due date on the MRP. The DBR Scheduling system of the TOC is excellent for adapting to production system change and suitable to make-to-order production small and medium compan. In this thesis, we make a system design using the Together(UML tool) and develope a production scheduling system using Microsoft Visual Basic.Net.

• Proceedings of the Korea Association of Information Systems Conference
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• 2003.11a
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• pp.55-63
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• 2003

Workflow Management System (WFMS) is a software system to support an efficient execution, control and management of complex business processes. Since traditional commercial systems mainly focus on automating processes, they don't have methods for enhancing the task performer's efficiency. In this paper, we propose a new method of executing business processes more efficiently in that a whole process is scheduled considering the degree of the participants' workload. The method allows managing the largest constraints among constituent resources of the process. We utilize DBR scheduling techniques to develop the method. We first consider the differences between workflow process models and DBR application models, and then develop the modified drum, buffer and rope. This leads us to develop WF-DBR (WorkFlow-DBR) that can control the proper size of the task performers' work list and arrival rate of process instances. Use of WF-DBR improves the efficiency of the whole process as well as the participants' working condition. We then carry out a set of simulation experiments and compare the effectiveness of our approach with that of scheduling techniques used in existing systems.

• IE interfaces
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• v.25 no.1
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• pp.106-113
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• 2012

There are few factors like a due date observance of the customer's order, reducing the manufacturing lead time, and minimizing the inventory investment to successfully run the manufacturing system. It is difficult for corporation and a person concerned to be offered indicators to achieve few factors mentioned above from complex manufacturing systems having much fluctuations. Simplified-DBR based on TOC(Theory of Constraints) is a management paradigm which can offer indicators to effectively face with fluctuating market's needs when market's demand is smaller than a capacity of manufacturing system. This paper is offering a core indicator and management model which is needed to successfully run the manufacturing system for corporation and a person concerned who have short experience and knowledge and newly construct Sinplified-DBR manufacturing system. Thus, this paper provides a systemic guidance in the offered model through the simulation.

• Journal of the Korea Safety Management & Science
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• v.4 no.1
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• pp.131-139
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• 2002

Since introducing the "Theory of Constraints" by Goldratt, its effect was verified by lots of scholars, men of enterprise. These days it is also introducing and studying in this country with good results. The objective of this study is to show how to determine the constraint resources on DBR scheduling. Actually, previous studies based on the line which just think a load/capacity rate on doing scheduling. This study will show a scheduling method which reflects multi-parameters. It could be a standard to reflect real manufacturing surroundings. On calculating a priority of each resources, we classified factors with subjective and objective factors. And we propose a decision model to incorporate values assigned by a group of experts on different factors to select a critical resource. On deploying this model, SN ratio of Taguchi method for each of subjective and objective factors will be used. And we propose a procedure which is organized with 7 steps. To understand the logic, a numerical manufacturing simulation will be presented. This method is a incorporating decision model on determining the constraint on multi parameters with experts.h experts.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.652-659
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• 2003

이 논문은 TOC(Theoyv of Constraints) 기반의 DBR(Dyum-Buffey-Rope) 스케줄링 기법의 기본 개념을 소개하고. 이 기법이 저음 개발되어 오늘에 이르기까지 실제 생산기업에 적용되고 이론적으로 발전되어온 역사를 문헌을 중심으로 고찰하는 것이다. DBR 스케줄링 기법의 기본 개념 및 구조를 간단한 사례를 중심으로 설명하였으며. 1998년 처음 개발된 이후 발표된 논문을 중심으로 프로세스 산업적용, 반도체 산업 적용, DBR과 ERP 통합, MPS 문제, 버퍼 크기 문제, 공급망 관리와의 연계, VAT 분석, JIT와의 연계, 서비스 산업에의 적용. 일반 산업응용 사례, DBR 시스템 개발 등으로 나누어 문한 분석을 한 결과를 제시하였다. 마지막으로 향후 DBR 기법의 발전 방향 등에 대하여 논의하였다.

• Journal of Korean Institute of Industrial Engineers
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• v.28 no.4
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• pp.344-350
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• 2002

An alternative to traditional production planning and control systems such as MRP and JIT is the drum-buffer-rope(DBR). Using the DBR system, companies can achieve a large reduction of work-in-process (WIP) and finished-goods inventories (FGI), significant improvement in scheduling performance, and substantial earnings increase. The purpose of this paper is to analyze the effect of the DBR system in a serial production line. Using Markov process, we modeled a DBR system with three stages. For the model developed, we analyze the system characteristics and then present an optimization model for system design. The system performance is also analyzed through sensitivity analysis.

• Journal of Korean Society for Quality Management
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• v.32 no.2
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• pp.154-167
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• 2004

The TOC/DBR and Six Sigma are the most attention-getting concepts for managing manufacturing companies in Korea. Using the ideas and methods of the TOC/DBR, companies can achieve a large reduction of work-in-process and finished-good inventories, significant improvement in scheduling performance, and substantial earnings increase. The Six Sigma approach derives the overall process of selecting the right projects based on their potential to improve performance metrics and selecting/training the right people to get the business results. These two concepts have different backgrounds and different viewpoints for production systems. So, if the two concepts collaborate each other, the synergy effects to innovate production systems can be expected. This paper proposes a new approach to implement the TOC/DBR concepts in production systems. This approach uses some concepts of Six Sigma which stresses educations, project approaches (step by step procedure using a Roadmap), and improvement philosophy.