• 지능정보연구
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• 제13권4호
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• pp.121-135
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• 2007

문제의 제약조건을 명확히 표현하고 휴리스틱 탐색에 의하여 스케쥴링을 형성하는 제약조건 중심의 스케쥴링 기법은 실세계의 스케쥴링 문제에 성공적으로 적용되어 왔다. 하지만, 기존의 제약조건 중심의 스케쥴링 연구에서 스케쥴링의 목적을 표현하고 최적화하는데 관련된 연구는 부족한 상황이다. 특히 비용 목적함수는 다양한 비즈니스 계획의 효과를 분석하는 기업의사결정에서 매우 중요 하다고 평가된다. 이 연구의 목적은 자원 용량이나 일시적인 제약조건을 만족하면서 지연비용 및 재고비용을 포함한 스케쥴링의 전체 비용을 명확하게 표현하고 최적화하는 것이다. 비용기반 스케쥴링 프레임워크에서, 동일한 작업 내에 일시적인 제약조건을 만들어 가면서 비용함수를 개선해 나가는 비용 전파 알고리즘을 제시하였다.

• 산업경영시스템학회지
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• 제19권40호
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• pp.203-217
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• 1996

This thesis describes a quantitative decision-making of production planning system. A mathmatical model of Linear Programming is used set up a production scheuling under the assumption. As the emphasis is laid on the applicability of the developed model, the linrar programming is applied to establish the production schedule for "F" furniture company which produces kitchin cabinet and OA furniture, The optimal solution is obtained by using the LP package, QBS. By the solution reduced to 14% of work force compared with the real data during all of the planning horizon. And it is also possible to reduce the work-force of the lowest level of employee by 10% for the reasonable management. There are some limitations in computerized data processing, which is only considering the economic costs without considering any external environment of case enterprise. As a result, it is shown that the LP model is very useful method of make aggregate production schedule. schedule.

• 한국산업융합학회 논문집
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• 제25권1호
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• pp.79-86
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• 2022

In general, since the types and types of ships, so complex and various variables are included to measure the amount of construction work. In addition, it is mot easy to predict the schedule or the number of working hours before ship construction, and it is also mostly inaccurate. As a result, the master plan is manually drawn up by the expert's experience, but there are limitations due to various factors. Medium and large shipyards are operating APS(Advanced Planning and Scheduling) system that reflects industrial characteristics to improve productivity in the planning stage, and utilize information from systems such as ERP(Enterprise Resource Planning) system and MES (Manufacturing Execution System). On the other hand, small shipyards rely mostly on manual work such as Excel work based on the experience of the workers. Therefore, this study intends to develop a master plan management system that can efficiently manage the production process from the business planning stage in consideration of the characteristics of small shipyards.

• 대한산업공학회지
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• 제26권1호
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• pp.17-26
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• 2000

This paper presents an integrated order scheduling method with the improved DRP concept for multi-echelon distribution system that has the constraint of limited production capacity of producers. The proposed method reflects the dynamic characteristics of inventory level changes in the regional and central distribution center. The simulation is done with two models : the traditional DRP method and the proposed method presented in this paper. From the results, the latter is more efficient than the former in cost, customer's service level as well as balanced production load on each producer.

• 한국CDE학회논문집
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• 제11권2호
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• pp.115-127
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• 2006

At the initial design stage, the generation process of the production material information of a building block and the simulation process of the block erection, which are required to perform the production planning and scheduling, have been manually performed by using 2D drawings, data of parent ships, and design experiences. To make these processes automatic, the accurate generation method of the production material information and the convenient simulation method of the block erection using the 3D CAD model, which was generated from the initial hull structural design system early developed by us, were proposed in this study. For this, a 3D CAD model for a whole hull structure was generated first, and the block division method for dividing the 3D CAD model into several building blocks was proposed. The generation method of the production material information for calculating the weight, center of gravity, painting area, joint length, etc. of a building block was proposed as well. Moreover, the simulation method of the block erection was proposed. Finally, to evaluate the efficiency of the proposed methods for the generation of the production material information and the simulation of the block erection, these methods were applied to corresponding processes of a deadweight 300,000 ton VLCC (Very Large Crude oil Carrier). As a result, it was shown that the production material information of a building block can be accurately generated and the block erection can be conveniently simulated in the initial design stage.

• 한국CDE학회논문집
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• 제15권1호
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• pp.1-10
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• 2010

Recently, a shipyard is making every effort to efficiently manage equipments of resources such as a gantry crane, transporter, and so on. So far block lifting scheduling of a gantry crane has been manually performed by a manager of the shipyard, and thus it took much time to get scheduling results and moreover the quality of them was not optimal. To improve this, a block lifting scheduling system of the gantry crane using optimization techniques was developed in this study. First, a block lifting scheduling problem was mathematically formulated as a multi-objective optimization problem, considering the minimization of travel distance at an idle state and wire replacement during block lifting. Then, to solve the problem, a meta-heuristic optimization algorithm based on the genetic algorithm was proposed. To evaluate the efficiency and applicability of the developed system, it was applied to an actual block lifting scheduling problem of the shipyard. The result shows that blocks can be efficiently lifted by the gantry crane using the developed system, compared to manual scheduling by a manager.

• Industrial Engineering and Management Systems
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• 제7권2호
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• pp.84-92
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• 2008

Scheduling is one of the most important issues in the planning and operation of production systems. This paper investigates a general job shop scheduling problem with reentrant work flows and sequence dependent setup times. The disjunctive graph representation is used to capture the interactions between machines in job shop. Based on this representation, four two-phase heuristic procedures are proposed to obtain near optimal solutions for this problem. The obtained solutions in the first phase are substantially improved by reversing the direction of some critical disjunctive arcs of the graph in the second phase. A comparative study is conducted to examine the performance of these proposed algorithms.

• 산업경영시스템학회지
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• 제10권16호
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• pp.19-26
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• 1987

Since many small and medium sized enterprises have lack of funds to install the full scale Computer Aided Process Planning this study has been attempted to develop a part of computer generated production information system for a start. The system is programmed by DBASE III and BASIC languages for the IBM-PC competables for the sake of user's convenience. The system consisted of four major parts. The first part is a computerized work measurement system for applying WF predetermined time standards. The second part is a computerized forecasting and loading system for applying various statistical techniques. The third part is a GT scheduling system programmed by BASIC for applying heuristic scheduling method. Finally, the last part is a simulation system for GT scheduling efficiency test which is programmed by SIMAN simulation language.

• 산업공학
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• 제19권1호
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• pp.34-42
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• 2006

This paper presents a scheme for a hierarchical production scheduling and control system for a refrigerator factory with mixed model assembly lines. The setting of the factory is as follows. There are three mixed-model assembly lines called main line A, B and C and two batch lines that supply parts to the main lines. For each of the main lines, three work-centers are dedicated to them. The sub-lines and work-centers produce parts in batch type. An incoming production order from the master planner is characterized by its product type, amount, and due date. Under this situation, the proposed scheme has several features to schedule and control the above mentioned factory; 1) select the starting time and the place (assembly line) for an order processing, 2) devise a way to control orders to be processed as scheduled, and 3) reschedule orders when something unexpected happen. Finally, this paper provides a case study where the proposed scheme is applied to.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2003년도 추계학술대회
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• pp.93-96
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• 2003

In this regard, the newly focused logistics information system makes reducing the expenses of whole logistic available by cutting down the expenses of materials, transportation and stock and also, it allows the company to cut down the procurement expense through the reduced lead-time and rationalize producing plans by eliminating the uncertain orders and fluctuation in procurement. It further more optimizes the efficiency of over all productions by meeting the dead line for delivery to the customers. In the recent environment of globalization where fierce competitions exist between manufacturers, logistics plays important role in the strategies of companies, and managements of companies try their best efforts in establishing the strategy to accomplish the innovative relationship between supply chain channels. Therefore, in this study, we try to suggest the model of consolidated logistics system that is integrated logistics information system with suggesting the better way of logistics and comparative analysis with logistics system to resolve the difficulties numbers of companies face after realizing what logistics information system is in Korea.