• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.44
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• pp.47-60
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• 1997

Today, more and more information is processed in the shop floor The main function of the shop floor is more enlarged and enriched by the integration of information processing tasks. So, we have designed the shop floor control information system(SFCIS) considered using the IDEF methodology. The SFCIS consists of 5 sub-systems, which are the manufacturing data base, the order release, the dynamic scheduling, the process control, and the output analysis sub-system. And we have constructed the SFCIS for long-cycle products, which have production lead time longer than the period of production planning horizon.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.421-424
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• 2004

This paper focuses on the problem of determining the quantity and timing of disassembling used products while satisfying the demand of their parts or components over a planning horizon. The case of multiple product types with parts commonality is considered for the objective of minimizing the sum of setup, disassembly operation, and inventory holding costs. A heuristic is suggested, in which an initial solution is obtained using a linear programming relaxation method, and then improved by perturbing the given solution using a dynamic programming approach and a look-ahead check while considering the trade-offs among different cost factors.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.699-706
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• 2005

증가하는 소비의 추세, 한정된 자원, 폐기물 처분등의 문제로 인하여, remanufacturing 에 대한 관심이 더욱 높아져가고 있다. Remanufacturing 에 대한 생산계획 및 스케줄링은 높은 불확실성으로 인하여 기존의 방법들과 별개로 다루어져야 한다. 본 연구에서는 manufacturing/remanufacturing 생산 시스템에서의 생산계획을 위한 수정된 유전 알고리즘(GA)을 제안하였다. GA 의 chromosome 은 각 부품의 생산 수준을 의미하며, 알고리즘을 이용하여 중간조립품과 최종제품의 분해/조립 계획을 결정할 수 있다. 임의로 생성된 문제들에 대해 실험한 결과, 다양한 문제들에 대하여 적용 가능하다는 것을 알 수 있었다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.207-214
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• 2005

Productivity and quality stability are very important competitive factors in PCB manufacturing lines that process the multiple types of products with the mixed process flows under frequent order information changes. MES is an appropriate IT solution to solve these problems in the medium-sized PCB manufacturing company. This paper introduces the MES development and its effects for a medium-sized PCB manufacturing company. The main functions of an implemented MES are delivery simulation, production scheduling, and production process monitoring. Productivity are improved up to $10{\sim}20%$ and manufacturing lead times per order are shortened up to 2 days according to the manufacturing scenarios.

• Korean Journal of Computational Design and Engineering
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• v.13 no.1
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• pp.18-26
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• 2008

Shipbuilding industries have been struggling to reduce production time and cost of their products in many aspects. Manufacturing systems have been changed, new production lines and robots have been installed, and new planning and scheduling systems have been adopted in order to achieve shorter time-to-market and higher productivity. Simulation based manufacturing, digital manufacturing, or virtual manufacturing simulation, whatever the name means, is an approach to achieve such a goal. In order to improve productivity in a shipbuilding process at a shipyard, a digital shipyard development has been driven. This paper proposed how to implement the digital shipyard, what to do with it, and what to obtain from it. This digital shipyard will help simulate and optimize the entire shipbuilding life cycle with its virtual environment through shipbuilding process from the initial development stage to the launch.

• IE interfaces
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• v.15 no.1
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• pp.99-106
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• 2002

A recently developed alternative to traditional production planning and control systems such as material requirement planning(MRP) and just-in-time(JIT) is the drum-buffer-rope(DBR). The DBR now being implemented in growing number of manufacturing organizations enables better scheduling and decision making on the shop floor. In implementing the DBR, however, an information system is usually needed to transmit the signal that runs from the constraint to material release. In this paper we propose a different mechanism to transmit the signal in the case that the demand of product is stable, which uses the well-known Kanban system. To improve the reality, this paper shows and example of the Kanban format, its operation, and calculation of the number of Kanbans.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.190-193
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• 1996

In recent, most of automobile industries adopt the concept of Just In Time production. The paternal manufacturers require their suppliers to supply parts just in time. It is very important for a subcontractor to produce the parts in the appointed time of delivery. This study develops a production information system for Woosin Industry, which is one of such subcontractor of Hundai Motors Company(HNC). The system is developed on Client/Server system. Firstly, three modules are developed, i.e., scheduling module to make a schedule, the subsystem of sales management to deal with the information about order of HMC, delivery of parts, and bill collecting, and the module for supporting material requirement planning and purchace of material.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.155-162
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• 1994

The Japanese "Just-In-Time" technique reduces inventory and unnecessary factors. This technique makes the success of Japanese firms, therefore many Korean firms try to apply it to their situation. But the technique doesn't bare the same success in Korean firms. This paper, therefore, considers the different situations between Korean rim and Japanese firm, then simulates the Pull system and Push system for a multiline, multistage production system. This paper drives the different results of simulation according to variable processing times, variable demand, set-up time and shortages in Pull system and Push system using GPSS. The results show that the performance of Pull system is lower than Push system's in variable master production scheduling and variable processing times.ing times.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.105-112
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• 1994

The purpose of this paper is to develope a heuristic algorithm to maximize reduction rate of the processing time by the connection of neighbored machines. A method to calculate the start-lag and stop-lag for the overlapping production is proposed and applied. The heuristic procedure of this paper has 3 steps. In the first and second step, the job oriented procedure is applied. In the final step, the operation oriented procedure is applied. In order to evaluate the performance of this algorithm, three kinds of performance measures are selected and randomly generated problems are tested.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.3
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• pp.137-158
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• 1992

We study the Multiple Product Single Facility Stockout Avoidance Problem (SAP). That is the problem of determining, given initial inventories, whether there is a multiple product single facility production schedule that avoids stockouts over a given time horizon. The optimization version of the SAP where stockouts are pnelized linearly is also studied. We call this problem the Weighted Stockout Problem (WSP). Both problems are NP-hard in the strong sense. We develop Mixed Integer Linear Programming (MIP) formulations for both the SAP and the WSP. In addition, several heuristic algorithms are presented and performances are tested using computational experiments. We show that there exist polynomial algorithms for some special cases of the SAP and the WSP. We also present a method to phase into a target cyclic schedule for infinite horizon problems. These can be used as a practical scheduling tool for temporarily overloaded facilities or to reschedule production after a disruption.