• Journal of the Korea Safety Management & Science
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• v.6 no.1
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• pp.97-108
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• 2004

This Study will introduce the concept of A TP(A vailable To Promise) and CTP(Capable to Promise) through the existing study, the process analysis of CTP, the modeling of algorithm and the embodiment of system. This research considers the environment of using Job-Shop method. The CTP algorithm models using LPST(Latest Possible Start Time) and EPST(Earliest Possible Start Time) method especially. It is important part of executing CTP systems. The CTP modeling and implementing develops to system which is capable to implement in the various business environment through additional and continuous research.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.387-390
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• 2004

인터넷 기반의 글로벌 e-비즈니스 환경에서 고객과 실시간으로 납기를 확약할 수 있는 기능이 수주생산 기업의 경쟁력의 핵심요소로 부상하고 있다. 수주생산형 제조기업이 납기확약을 위해서는 수주시 생산능력을 고려하여 납기를 확약해줄 수 있는 생산능력 납기확약 시뮬레이션 엔진을 위한 알고리즘이 필요하다. 본 연구에서는 이를 위한 생산능력 납기확약 시뮬레이션 엔진의 알고리즘을 제시한다. 본 연구의 결과로 복수의 공장과 다양한 생산라인을 갖춘 복잡한 제조시스템의 스케쥴링을 빠른 시간 내에 도출해 냄으로써 고객에게 빠른 시간내에 정확한 납기확약이 가능해져 기업 경쟁력 강화에 크게 기여할수 있다.

• Journal of the Korean Operations Research and Management Science Society
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• v.13 no.1
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• pp.57-57
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• 1988

This paper develops an adaptive scheduling policy for flexible manufacturing systems. The inductive learning methodology used for constructing this state-dependent scheduling policy provides and understanding of the relative importance of the various system parameters in determining the appropriate scheduling rule. Experimental studies indicated the superiority of the suggested approach over the alternative approach involving the repeated application of a single scheduling rule for randomly generated test problems as well as a real system, and under both stationary and nonstationary conditions. In particular, its relative performance improves further when there are frequent disruptions, and when disruptions are caused by the introduction of tiiight due date jobs, one of the most common surces of disruptions in most manufacturing systems.

• Journal of the Korean Operations Research and Management Science Society
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• v.20 no.1
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• pp.115-130
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• 1995

This paper considers a single machine nonpreemptive scheduling problem with a given common due date. In the problem, the optimal job sequence is sought to minimize the sum of earliness/tardiness and flow time measures in the situation where all jobs are available at time zero, and weights per unit length of earliness/tardiness and flow time are V and W, respectively. Some dominant solution properties are characterized to deriva both an optimal starting time for an arbitrary sequence and sequence improvement rules. The optimal schedule is found to the case W .geq. V/. By the way, it is difficult to find the optimal schedule for the case W < V. Therefore, the derived properties are put on together to construct a heuristic solution algorithm for the case W < V, and its effectiveness is rated at the mean relative error of about 3% on randomly generated numerical problems.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.365-368
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• 1996

The setting of the factory under this study is as the following. There are multiple assembly lines. Each line can handle any of given set of products. Furthermore each line is capable of assembling several products concurrently, i.e. mixed model assembly line. An incoming production order is characterized by its due-date, product type and quantity. Under this setting we first have to select the starting time and the place(assembly line) for an order to be processed. We also have to devise a way to control orders to be manufactured as scheduled. Finally there should be a mean to reschedule orders when something unexpected happens. This paper offers a scheme that provides the above mentioned necessities. It also provides a case where the scheme is applied.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.4
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• pp.143-153
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• 2001

In this study we develop a computer simulation model to evaluate the effects of various production and order processing policies measured in terms of on-time delivery rate and average waiting time of job orders. Policies considered include : eliminating inflated due date, lot splitting, loss time reduction, attaining full flexibility in production lines, and selective order promising scheme. Actual order-production data from a chemical company were used in the simulation model. Based on the simulation results, we make several suggestions that can significantly reduce the production lead time and increase the on-time delivery rate.

• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.1
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• pp.117-129
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• 2008

Make-to-order manufacturers with multiple plants at multiple sites need to have the ability to quickly determine which plant will produce which customer order to meet the due date and minimize the transportation cost from the plants to the customer. Balancing the work loads and minimizing setups and make-span are also of great concern. Solving such scheduling problems usually takes a long time. We propose a new approach, which we call 'preprocessing', for resolving such complex problems. In preprocessing scheme, a 'good' a priori schedule is prepared and maintained using unconfirmed order information. Upon the confirmation of orders. the preprocessed schedule is quickly modified to obtain the final schedule. We present a preprocessing solution algorithm for multi-site constraint scheduling problem (MSCSP) using genetic algorithm; and conduct computational experiments to evaluate the performance of the algorithm.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.1
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• pp.27-41
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• 2005

This paper considers identical parallel machine scheduling problem. Each job has a processing time. due date. weight and family type. If a different type of job is followed by prior job. a family setup is incurred. A two phased heuristic is presented for minimizing the sum of weighted tardiness. In the first phase. using roiling horizon technique. group each job into same family and schedule each family. In the second phase. assign each job to machines using schedule obtained in the first phase. Extensive computational experiments and comparisons among other algorithms are carried out to show the efficiency of the proposed algorithm.

• Journal of Korean Society for Quality Management
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• v.17 no.1
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• pp.116-124
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• 1989

A multi-period production-inventory scheduling model, which extends the customary dynamic lot sizing model to the one for deteriorating items, is developed. The amount of deterioration during a period is assumed to be proportional to the on-hand inventory at the end of the period. It is futher assumed that the deterioration rates vary from period to period. In addtion, an expediting cost due to the delay of outstanding order is included and it is allowed to offset the order release date in advance, instead, in order to avoid incurring the cost. Finally, a quasi-WW algorithm corresponding to the Wagar-Whitin algorithm is proposed to obtain the optimal production-inventory schedules.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.157-160
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• 2003

In order to reduce the construction cost and period without degrading the quality, construction companies are making a lot of efforts to prefabricate and mechanize the construction process, and introducing and utilizing various techniques of construction time management in the process of construction. However, due to the various factors (such as weather conditions, labor factors, supply of equipment and materials, safety accident, etc) in the process of construction, construction projects are not frequently completed within the scheduled Period. This research is to examine the current status of construction time management and factors causing delay in construction with regard to the concrete work (such as form work, steel reinforcement, and concrete work) in building apartments.