• Management Science and Financial Engineering
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• v.2 no.1
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• pp.19-51
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• 1996

We suggest a distributed framework for task assignment in the computer-controlled shop floor where each of the resource agents and part agents acts like an independent profit maker. The job allocation problem is formulated as a linear programming problem. The LP formulation is analyzed to provide a rationale for the distributed task assignment procedure. We suggest an auction based negotiation procedure including a price-based bid construction and a price revising mechanism. The performance of the suggested procedure is compared with those of an LP formulation and conventional dispatching procedures by simulation experiments.

• Management Science and Financial Engineering
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• v.3 no.2
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• pp.29-43
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• 1997

Many heuristics have been developed in order to overcome the computational complexity of job shop problems. In this research, we develop a new heuristic by selecting four simple dispatching rules, i.e., SPT, LPT, SR and LR, dynamically as scheduling proceeds. The selection is accomplished by using artificial neural networks. As a result of testing on 50 problems, the makespan obtained by our heuristic is, on the average, 13.0% shorter than the longest makespan, and 0.4% shorter than the shortest makespan obtained by existing dispatching rules.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.1
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• pp.67-95
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• 1998

This research addresses flow time prediction in the dynamic unbalanced job shop scheduling environment. The specific purpose of the research is to develop the job flow time prediction model in the dynamic unbalance djob shop. Such factors as job characteristics, job shop status, characteristics of the shop workload, shop dispatching rules, shop structure, etc, are considered in the prediction model. The regression prediction approach is analyzed within a dynamic, make-to-order job shop simulation model. Mean Absolute Lateness (MAL) and Mean Relative Error (MRE) are used to compare and evaluate alternative regression models devloped in this research.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.214-214
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• 1998

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.510-510
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• 1995

• Korean Management Science Review
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• v.13 no.1
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• pp.1-12
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• 1996

This paper deals with production scheduling of block assembly shop in shipbuilding company. The Objectives of the schedule are leveling of daily total workload and fair assignment of workload to each department of the shop. Optimizing the objectives, we consider some restrictions which consisit of block due dates, workability of each department, and space restriction. We formulate the problem in mathematical form. But the model is too complex to find the optimal solution (the problem is NP-complete) and we use the genetic algorithm to find a good solution.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.216-219
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• 1998

This study proposes JPT(Job-Pair Tardiness) that choose operation to be expected to generate better schedule consequence in comparing schedulable operation sets in pair to minimize total tardiness evaluation function in performing scheduling. In result of comparison with existing assignment rules. JPT generates better solution than most other rules in all kinds of problems. So it is anticipated that this is used for initial solution of heuristic and is used for finding more improved solution.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.135-142
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• 1994

생산시스템을 구성하는 자동화 요소들을 물리적으로 연결하는 물류시스템은 공장자동화를 구축하는데 핵심 요소로서 통합시스템 운영차원에서의 체계적인 정보구조를 가져야 한다. 따라서 본 연구에서는 물류시스템을 대표하는 AS/RS와 AGV시스템의 제어 Protocol 해석과 cell level에서 관리되어야 할 정보를 분석하여 정보흐름을 중심으로 한 물류시스템용 통합정보체계를 설계하였다. 또한, 물류 cell level의 통합차원에서 필요로 하는 제어정보 및 감시정보의 정의와 시스템 scheduling에서 고려될 상황정보를 설계하였다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.377-380
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• 1996

Most manufacturing systems are large and complex. It is natural to divide the control into a hierarchy consisting of a number fo different levels. Each levels is characterized by the length of the planning horizon and the kind of data required for the decision making process. This paper describes an approach for the incorporation of Maintenance times into a hierachical scheduling for a failure prone flexible manufacturing system. The Maintenance should not be performed too often because of the resulting reduction of capacity. The machine failure and preventive maintenance are considered simultaneously.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.175-178
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• 2000

BOM has been widely used to manufacturing, product design and scheduling. There are several bug differences between Manufacturing BOM and Engineering BOM, which cause a lot of problems. A study to integrate both manufacturing BOM and Engineering BOM is researching to solve those problems. This thesis presents a extended Engineering BOM concepts considering assembly sequence model.