• 대한산업공학회지
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• 제32권2호
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• pp.98-103
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• 2006

In this research, the single machine capacitated lot-sizing and scheduling problem with sequence- dependent setup costs and setup times (CLSPSD) is considered. This problem is the extension of capacitated lot-sizing and scheduling problem (CLSP) with an additional assumption on sequence-dependent setup costs and setup times. The objective of the problem is minimizing the sum of production costs, inventory holding costs and setup costs satisfying customers' demands. It is known that the CLSPSD is NP-hard. In this paper, the MIP formulation is presented. To handle the problem more efficiently, a conceptual model is suggested, and one of the well-known meta-heuristics, the simulated annealing approach is applied. To illustrate the performance of this approach, various instances are tested and the results of this algorithm are compared with those of the CLPEX. Computational results show that this approach generates optimal or nearly optimal solutions.

• International Journal of Quality Innovation
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• 제6권3호
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• pp.70-94
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• 2005

The IC packaging industry heavily relies on shop floor information, necessitating the development of a model to flexibly define shop floor information and timely handle manufacturing data. This study presents a novel data model of product manufacturing flow to define shop floor information to effectively respond to accelerated developments in IC package industry. The proposed data model consists of four modules: operation template setup, general process setup, enhanced bill of manufacture (EBOMfr) setup, and work-order process setup. The data model can flexibly define the required shop floor information and decision rules for shop floor product manufacturing flow, allowing one to easily adopt changes of the product and on the shop floor. However, to handle floor dynamics of the IC packaging industry, this work also proposes a WIP (i.e. work-in-process) system for monitoring and controlling the product manufacturing flow on the shop floor. The WIP system integrates the data model with a WIP execution module. Furthermore, an illustrative example, the MIRL WIP System, developed by Mechanical Industrial Research Laboratories of Industrial Technology Research Institute, demonstrates the effectiveness of the proposed model.

• 산업경영시스템학회지
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• 제13권21호
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• pp.91-100
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• 1990

This paper is concerned with the development of optimal algorithms for multi-stage flowshop scheduling problems with sequence dependent setup times. In the previous researches the setup time of a job is considered to be able to begin at the earliest opportunity given a particular sequence at the start of operations. In this paper the setup time of a job is considered to be able to begin only at the completion of that job on the previous machine to reflect the effects of the setup time to the performance measure of sequence dependent setup time flowshop scheduling. The results of the study consist of two areas; first, a general integer programming(IP) model is formulated and a nixed integer linear programming(MILP) model is also formulated by introducing a new binary variable. Second a depth-first branch and bound algorithm is developed. To reduce the computational burdens we use the best heuristic schedule developed by Choi(1989) as the first trial. The experiments for developed algorithm are designed for a 4$\times$3$\times$3 factorial design with 360 observations. The experimental factors are PS(ratio of processing time to setup time), M(number of machines), N(number of jobs).

• 한국전자거래학회지
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• 제24권3호
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• pp.99-110
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• 2019

4차 산업혁명이 진행되면서 제조업에서 사물인터넷(IoT), 머신러닝과 같은 지능정보기술을 적용하는 사례가 증가하고 있다. 반도체/LCD/타이어 제조공정에서는 납기일(due date)을 준수하면서 작업물 종류 변경(Job change)으로 인한 작업 준비 비용(Setup Cost)을 최소화하는 일정계획을 수립하는 것이 효과적인 제품 생산을 위해 매우 중요하다. 따라서 본 연구에서는 병렬기계에서 딥러닝 기반의 납기 지연과 작업 준비 비용 최소화를 달성하는 일정계획 생성 모델을 제안한다. 제안한 모델은 과거의 많은 데이터를 이용하여 고려되어지는 주문에 대해 작업 준비와 납기 지연을 최소화하는 패턴을 학습한다. 따라서 세 가지 주문 리스트의 난이도에 따른 실험 결과, 본 연구에서 제안한 기법이 기존의 우선순위 규칙보다 성능이 우수하다는 것을 확인하였다.

• 한국정보과학회논문지:정보통신
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• 제29권4호
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• pp.405-411
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• 2002

광 인터넷에서 광 전달망과 제어평면의 분리를 실현하는 개방형 인터페이스에 대한 연구는 OIF의 ISI, ITU-T ASON의 CCI 그리고 IETF의 광 스위칭을 위한 GSMP 확장 등이 있다. 이러한 개방형 인터페이스 기술들은 망에서의 다양한 융통성을 제공하는 반면에 전통적인 스위치-대-스위치 연결 설정에 비하여 지연이 길다. 본 논문에서는 광 인터넷의 개방형 인터페이스에서 연결 설정 지연을 줄이기 위하여 병렬형 연동 모델을 채택 한다. 병렬형 연동 모델에서는 네트워크 상태에 대한 스위치 제어기의 캐쉴 능력을 기반으로 연결 설정을 위한 신호 프로토콜과 GSMP 프로토콜 사이의 연동 절차를 병렬로 수행한다. 시뮬레이션을 통하여 본 논문에서 채택한 병렬형 연동 모델과 기존의 순차형 연동 모델에 대한 연결 설정 지연과 완료율을 비교 분석하였다. 시뮬레이션 결과 두 모델이 완료율 면에서는 거의 일치하며, 연결 설정 지연 면에서는 병렬형 모델이 순차형 모델에 비하여 평균 30% 향상됨을 알 수 있었다.

• 한국전자거래학회지
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• 제24권3호
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• pp.19-33
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• 2019

최근 제조업체들은 제품의 생산방식이 고도화 되고, 복잡해지면서 생산 장비를 효율적으로 사용하는데 어려움을 겪고 있다. 제조공정의 효율성을 방해하는 대표적인 요인들로는 작업물 종류 변경(job change)으로 인한 작업 준비 비용(Setup Cost) 등이 있다. 특히 반도체/LCD 공정과 같이 고가의 생산 장비를 사용하는 공정의 경우 장비의 효율적인 사용이 매우 중요한데, 상호 충돌하는 의사결정인 납기 준수를 최대화 하는 것과 작업물 종류 변경으로 인한 작업 준비 비용을 최소화 하는 것 사이에서 균형을 유지하는 것은 매우 어려운 일이다. 본 연구에서는 납기와 작업 준비 비용이 있는 병렬기계에서 강화학습을 활용하여 납기 및 셋업 비용의 최소화 목표를 달성하는 일정계획 모델을 개발하였다. 제안하는 모델은 DQN(Deep Q-Network) 일정계획 모델로 강화학습기반의 모델이다. 제안모델의 효율성을 측정하기 위해 DQN 모델과 기존에 개발하였던 심층 신경망 기반의 일정계획 생성기법과 휴리스틱 원칙의 결과를 비교하였다. 비교 결과 DQN 일정계획 생성기법이 심층신경망 방식과 휴리스틱 원칙에 비하여 납기 및 셋업 비용이 적은 것을 확인할 수 있었다.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2003년도 춘계학술대회논문집
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• pp.129-134
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• 2003

In this paper, we determine optimal reduction in the lead time and setup cost for some stochastic inventory models. And we propose more general model that allow the backorder rate as a control variable. We first assume that the lead time demand follows a normal distribution. And we assume that the backorder rate is dependent on the length of lead time through the amount of shortages. The stochastic models analyzed in this paper are the classical continuous and periodic review policy models with a mixture of backorders and lost sales. For each of these models, we provide a sufficient conditions for the uniqueness of the optimal operating policy. We also develop algorithms for solving these models and provide illustrative numerical examples.

• 산업경영시스템학회지
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• 제17권32호
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• pp.121-126
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• 1994

Setup Time Reduction is an important aspect of the Just-in-Time(JIT) and Zero Inventory(Zl) Concepts since it supports reductions in manufacturing lead times and inventories. It also enables small lot sizes and kanban systems implementation for material flow - achieving major improvements in production floor management. One concept fundamental to the pursuit of JIT production in Japan and other countries is adoption of a setup time reduction. This paper looks at the necessities of setup time reduction and the relations to machine utilization. By using an EOQ model for evaluate the effect of setup time reduction, we get the results that over 75 % reduction in setup time is obtain the desired results in the lot size reduction.

• 산업경영시스템학회지
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• 제12권19호
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• pp.79-88
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• 1989

This characteristics of process industries are high capital intensity, relatively long and sequence dependent setup times, and extremely limited capacity resources. The lot sizing, sequencing and limited capacity resources factors must he considered for production scheduling in these industries. This paper presents a mixed integer programming model for production scheduling. The economic trade offs between capacitated lot sizing flow shop scheduling and sequence dependent setup times also be compared with SMITH-DANIELS's model. As a results, it is shown that this paper has lower total cost, more efficient throughput than SMITH-DANIELS's model.

• 대한산업공학회지
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• 제21권1호
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• pp.67-84
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• 1995

Five-axis NC machining is advanced machining technology by which highly geometrically complicated parts can be machined accurately with high machinability. In this paper, we investigate the problems of determining the machinability and part setup orientation for a given surface models. We first develop kinematic model of the five-axis machines based on the axis configuration, then develop algorithms for determining the feasibility of machining by one setup(machinability) and the part orientation for the C,A and A,B type configuration. The machinability is determined by computationally efficient procedure for finding the intersection between the feasible area on the sphere and the numerical map called binary spherical map(BSM), and the part setup is chosen such that the rotational range is minimized among the feasible configurations. The developed algorithms are tested by numerical simulations, convincing they can be readily implemented on the CAD/CAM system as an automated process planner giving the efficient machine type and setup for NC machining.