• 대한산업공학회지
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• 제29권4호
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• pp.304-311
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• 2003

This paper considers a new variation of scheduling problems where jobs are dispatched in batches. The variation is the case where the batch sequence is fixed. The objective is to minimize the sum of the completion times of the batches. This simple environment has a variety of real world applications such as part kitting and customer order scheduling. We show that this problem is binary NP-complete when there exist two machines. For the same problem, we develop an optimal dynamic programming (DP) algorithm which runs in pseudo-polynomial time. We finally prove the optimality of the DP algorithm.

• 대한산업공학회지
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• 제24권3호
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• pp.345-357
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• 1998

This paper focuses on production planning and scheduling problems in an assembly system operating on a make-to-order basis. Due dates are considered as constraints in the problems, that is, tardiness is not allowed. Since the planning problem is a higher-level decision making than the scheduling problem, the scheduling problem is solved using a production plan obtained by solving the planning problem. We suggest heuristic procedures in which aggregated information is used when the production planning problem is solved while more detailed information is used when the scheduling problem is solved. Since a feasible schedule may not be obtained from a production plan, an iterative approach is employed in the two procedures to obtain a solution that is feasible for both the production planning and scheduling problems. Computational tests on randomly generated test problems are done to show the performance of these algorithms, and results are reported.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.101-104
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• 2002

Leading companies have embraced the new economy with new and innovative BTO models. Instead of conventional company-oriented manufacturing scheduling, customer-oriented scheduling method attracts more and more attention. To evaluate the delivery of customer order in advance, the real production capacity as well as procurement lead time should be taken into account. This paper describes a quasi-real-time order delivery estimation system using TOC(Theory of Constraints) based scheduling method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.370-375
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• 1992

This paper deals with the scheduling and simulation for FMC(Flexible Manufacturing Cells). In order to achieve CIM, there is a critical need to link factory level and machine level. The primary functions performed by this link for all jobs issued to the shop floor and cell include short-term scheduling and dynamic operational scheduling. Here, hierarchical control structure is introduced to define these functions. And Intelligent scheduling through expert module is adopted for efficiency of FMC operation. Computer simulation reveals that expert scheduling method is better than heuristics in various performance index.

• 전자공학회논문지A
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• 제29A권4호
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• pp.74-82
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• 1992

This paper deals with the scheduling problems, which are the most important subtask in High-level Synthesis. ILP(integer linear programming) formulations are used as a scheduling problem approach.For practical application to digital system design, we have concentrated our attentions on pipelined datapath scheduling. For experiment results, we choose the 5-th order digital wave filter as a benchmark and do the schedule. Finally, we can obtain better and near-optimal scheduling results.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.615-619
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• 2004

This paper considers a variation of customer order scheduling problems. The variation is the case where machine-job assignment is fixed, and the objective is to minimize the sum of the completion times of the batches. In customer order scheduling problems, jobs are dispatched in batches. While a machine can process only one job at a time, multiple machines can simultaneously process jobs in a batch. We first establish a couple of lower bounds. Then, we develop a dynamic programming (DP) algorithm that runs in exponential time on the number of batches when there exist two machines. For the same problem with arbitrary number of machines, we present two simple heuristics, which use simple scheduling rules such as shortest batch first and shortest makespan batch first rules. Finally, we empirically evaluate the heuristics.

• 한국경영과학회지
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• 제33권1호
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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 Multimedia Information System
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• 제1권2호
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• pp.95-100
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• 2014

Variable message signs (VMS) have the different sizes and a specific type according to the city scene and it has to be displayed by different message on the display panel in real-time. And VMS manufacturers must produce the different products in order to give a customized product to each order. In addition that, they should test and check the correct operation to each VMS product using the different message frame. That is very time and workers consuming and VMS emulator with an automatic variable message generator system is necessary. Also, the automatic message generator system is needed to real-time scheduling in order to display the message on the VMS panel like real world. In this paper, we design and implement the VMS emulator embedded the automatic message frame generator system with real-time scheduling which can set several parameters easily on the windows dialog.

• 산업공학
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• 제20권4호
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• pp.525-538
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• 2007

The importance of efficient container transportation becomes more significant each year due to the constant growth of the global marketplace, and studies focusing on shipping efficiency are becoming increasingly important. In this paper, we propose an approach for vehicle scheduling that decreases the number of vehicles required for freight commerce by analyzing and scheduling optimal routes. Container transportation can be classified into round and single-trip transportation, and each vehicle can be linked in a specific order based on the vehicle state after completing an order. We develop a mathematical model to determine the required number of vehicles with optimal routing, and a heuristic algorithm to perform vehicle scheduling for many orders in a significantly shorter duration. Finally, we tested some numerical examples and compared the developed model and the heuristic algorithm. We also developed a decision support system that can schedule vehicles based on the heuristic algorithm.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.620-623
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• 2004

Conventionally injection molds & dies are manufactured through an order-oriented manner. This brings unexpected orders into the shop floor such as hot order, re-work, and new types of mold & dies. Thus, there needs appropriate resource assignment plans considering the available times of machines and workers. Further, a scheduling system is required that can create work schedules periodically or by customers' requests. Yet, in small & medium sized mold & die makers, production schedules usually depend on the shop floor workers' experience and their manual preparation. Hence, developed in this study is a scheduling management system (SMS) based on order release and review (ORR) in small and medium sized mold & die companies. The proposed SMS considers delivery dates as well as flexible work schedules, so as to meet frequent changes of customers' order. The system can provide effective resource assigning and work scheduling plans, securing standard data associated with shop floors. Furthermore, the system pursues economical schedules for companies' needs, equipped with an available to promise (ATP) function that can effectively accommodate the changes of production plans.