• 산업공학
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• 제11권3호
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• pp.129-141
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• 1998

In this paper, a rescheduling procedure is developed for shipbuilding master production schedule. Shipyard initially develops backward production schedules for the entire shipbuilding process, and then refines the schedule by stage. The rescheduling procedure of this paper tries to resolve the schedule discrepancies between the outdoor backward schedule and the refined indoor schedule. Through the proposed rescheduling procedure, outdoor schedule can be successfully adjusted using buffer days and duration reduction. An Object-oriented program is also developed to automate the procedure. We can observe the improvement on productivity and quality of rescheduling works from the application of the developed procedure.

• 한국CDE학회논문집
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• 제17권2호
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• pp.111-122
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• 2012

Capacity planning plays an important role not only for master production plan but also for facility or layout design in shipbuilding. Product work breakdown structure, attributes of production resources, and production method or process data are associated in order to make the discrete event simulation model of shipyard layout plan. The production amount of each process and the process time is assumed to be stochastic. Based on the stochastic discrete event simulation model, the production capacity of each facility in shipyard is estimated. The stochastic model of product arrival time, process time and transferring time is introduced for each process. Also, the production capacity is estimated for the assumed master production schedule.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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• pp.104-106
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• 2004

In competitive electricity markets, the System Operator (SO) coordinates the overall maintenance schedules whenever the collective maintenance schedule reported to SO by Gencos in the pool does not satisfy the specified operating criteria, such as system reliability or supply adequacy. In this paper, we divide maintenance schedule problem into master-problem and sub-problem. Master-problem is schedule coordination and sub-problem is DC-optimal power flow. If sub-problem is infeasible, we use the algorithm of modifying operating criteria of master-problem.

• 대한전기학회논문지:전력기술부문A
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• 제54권7호
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• pp.352-357
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• 2005

In competitive electricity markets, the System Operator (SO) coordinates the overall maintenance schedules when the collective maintenance schedule reported to 50 by Gencos not satisfy the specified operating criteria, such as system reliability or supply adequacy. This paper presented a method that divides generator maintenance scheduling of the 50 into a master-problem and a sub-problem. Master-problem is schedule coordination and sub-problem is DC-optimal power flow. If sub-problem is infeasible, we use the algorithm of modifying operating criteria of master-problem. And, the 50 should use the open information only, because the information such as cost function of a generator and bidding Price is highly crucial for the strategies of profit maximization.

• 대한전기학회논문지:전력기술부문A
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• 제54권12호
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• pp.597-602
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• 2005

The introduction of competition in electricity market emphasizes the importance of sufficient transmission capacities to guarantee various electricity transactions. Therefore, when dispatch scheduling, transmission security constraints should be considered for the economic and stable electric power system operation. In this paper, we propose an optimal dispatch scheduling algorithm incorporating transmission security constraints. For solving these constraints, the dispatch scheduling problem is decomposed into a master problem to calculate a general optimal power flow (OPF) without transmission security constraints and several subproblems to inspect the feasibility of OPF solution under various transmission line contingencies. If a dispatch schedule given by the master problem violates transmission security constraints, then an additional constraint is imposed to the master problem. Through these iteration processes between the master problem and subproblems, an optimal dispatch schedule reflecting the post-contingency rescheduling is derived. Moreover, since interruptible loads can positively participate as generators in the competitive electricity market, we consider these interruptible loads active control variables. Numerical example demonstrates efficiency of the proposed algorithm.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1998년도 The Korea Society for Simulation 98 춘계학술대회 논문집
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• pp.106-110
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• 1998

Some successful scheduling systems are based on simulation technique. However, they are relatively expensive. A cost-effective solution is to apply general-purpose simulation software to the scheduling system. This paper is concerned with developing a simulation model for MPS(Master Production Schedule) evaluation system. The target system of the model is PC production system. AIM (Analyzer for Improving Manufacturing system), a well-known manufacturing oriented simulation software, is used for modeling tool. Eventually, the model can be included into an MPS evaluation system as simulation module and a scheduler can use the system to verify the MPS in advance.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1538-1545
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• 2004

In the train schedule plan corresponds to a master plan for transport services. This service plan must be constructed to minimize operational cost or maximize revenue considering transportation demands and resource capacities in the operation company, and it includes several sub-planning activities such as train operation frequency plan, train schedule plan, train capacity assignment plan, and rolling stock requirement plan. In this paper, we present profitability evaluation system for the current train schedule plan. The proposed system can be used for evaluating profitability by estimating train service revenue considering customer demands.

• 한국건설관리학회논문집
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• 제5권2호
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• pp.211-218
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• 2004

다수의 시설물을 보유한 기관에서는 유지보수와 리모델링(M/R) 프로젝트들이 동시에 진행되고 있다. 내부기능인력에 의해 프로젝트를 수행하는 자원제약 환경에서 프로젝트 관리자는 각 프로젝트의 완료일과 기관내 가용한 자원에 대한 제한을 고려하며 프로그램을 계획하고 관리하게 된다. 다중 자원제약 M/R 프로그램의 효과적 관리를 위해 이 논문은 장기적인 프로그램 계획축과 단기적인 일정창으로 구성되는 2단계 계층관리모델을 제안한다. 프로그램 플랜을 위한 연동계획기법은 연속되는 프로젝트 요청의 불확실성에 대처하기 위해 제안되었다. 일정창 속에서 마스터-일정계획을 수립하기 위해 개발된 PCR 일정계획 알고리즘은 M/R 프로그램에서의 작업반내 기능인력의 배치계획을 제공한다. 스프레드쉬트 인터페이스를 활용하여 M/R 프로그램의 일정계획 시스템을 개발하였고, 연속된 3개의 일정창으로 설계된 시뮬레이션 실험을 통해 개발된 일정계획 알고리즘과 기존의 자원제약 일정계획 휴리스틱의 성능을 비교하였다.

• 산업공학
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• 제9권2호
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• pp.143-158
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• 1996

This paper deals with the development of a software module for production planning and scheduling activities of an actual die-production management system. Scheduling problems, such as master schedule and detailed schedule, are the focal point of the whole article and they are considered in terms of operation procedures. Schedule-explosion module and load levelling module are the essential components of schedule management. The scheduling module allocates the resources, determines the process priority and the planned start and completion dates of processes. Rescheduling can be done to manipulate unforeseen situations that schedule is delayed owing to inducing defectives, machine breakdowns and lumpy demands. This study indicates a practical model for the die-producation management and helps to apply it for jobs in the real situation.

• Journal of Construction Engineering and Project Management
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• 제3권4호
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• pp.5-11
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• 2013

Construction industry is overwhelmed by delay and often has suffered cost and time overrun. In this context, Last Planner System (LPS) has been considered as a very useful tool for the management of the construction process. Many previous studies have reported its effectiveness in construction performance. This study aims to evaluate the level of importance of the Last Planner processes in the Vietnam construction industry (VCI), and analyze the existing barriers when implementing these processes in construction management. These barriers were collected based on previous studies from International Group for Lean Construction (IGLC). A survey was carried out through questionnaire. The respondents are been experienced people in construction project management. There are four processes of LPS that were investigated including master schedule, phase schedule, lookahead plan, and weekly work plan. The results showed that master schedule is the most important item when performing a construction project in the VCI. The highest degree of agreement belongs to 'owner - contractor' pair with 77.1% importance indices; whereas the lowest belongs to 'consultants - contractors' pair with 63.8% importance indices. Eventually, three barrier factors were extracted from factor analysis technique with 62.2% of variance explained.