• Korean Journal of Computational Design and Engineering
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• v.13 no.1
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• pp.18-26
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• 2008

Shipbuilding industries have been struggling to reduce production time and cost of their products in many aspects. Manufacturing systems have been changed, new production lines and robots have been installed, and new planning and scheduling systems have been adopted in order to achieve shorter time-to-market and higher productivity. Simulation based manufacturing, digital manufacturing, or virtual manufacturing simulation, whatever the name means, is an approach to achieve such a goal. In order to improve productivity in a shipbuilding process at a shipyard, a digital shipyard development has been driven. This paper proposed how to implement the digital shipyard, what to do with it, and what to obtain from it. This digital shipyard will help simulate and optimize the entire shipbuilding life cycle with its virtual environment through shipbuilding process from the initial development stage to the launch.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.4 s.142
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• pp.411-420
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• 2005

World leading company and research centers have invested much cost and effort into a PLM and digital manufacturing field to obtain their own competitiveness. We have been trying to apply a digital manufacturing, especially simulation to ship production process as a part of PLM implementation for a shipyard. A shipbuilding production system and processes have a complexity and a peculiarity different from other kinds of production systems. So, new analysis and modeling methodology is required to implement digital shipyard. which is a digital manufacturing system for a shipbuilding company. This paper suggests an analysis and simulation modeling methodologies for an implementation of a digital shipyard. New methodologies such as a database-merged simulation, a distributed simulation, a modular simulation with a model library and a 3-tire simulation framework are developed.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.2 s.140
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• pp.165-174
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• 2005

Recently, world leading companies on manufacturing field are trying to adopt a PLM methodology, which is a new production paradigm, for a survival and strengthening the competitiveness. Some projects for a digital shipyard including a methodology of a digital simulation framework are going on by Seoul national university and Samsung heavy industry. A Database methodology for a scheduling data, an interfacing methodology for a simulation input and output, and a synchronized simulation related methodology are required for enhancing the value of the digital simulation for shipbuilding. In this paper, such a methodologies and a related case study for a fabrication factory and an assembly factory are presented.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.2
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• pp.202-212
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• 2008

In recent days, global shipbuilding companies have been increasing their productivity or expanding their shipyards for a large amount of orders. Though, few researches about the shipyard layout designs have been studied. This research presents a simulation-based shipyard layout design framework to resolve the problems of the shipyard layout design. The shipyard layout design framework was developed on the basis of systems engineering method. The disciplined system engineering technique was guided by ISO/IEC 15288 during the planning phase of the shipyard layout design framework development. This framework suggests that how efficient and effective shipyard layout design could be got, that can satisfy the stakeholder of the layout. Furthermore, it is recommended that how the proposed shipyard layout should be verified and validated by digital simulation model. It is expected that the framework will contribute to not only the improvement of the existing shipyard but also the construction of the new shipyard.

• Proceedings of the Korea Society for Simulation Conference
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• 2003.11a
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• pp.185-192
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• 2003

Digital Manufacturing-based production could be very effective in shipbuilding in order to save costs and time, to increase safety for workers, and to prevent bottleneck processes in advance. Digital shipbuilding system, a simulation-based production tool, is being developed to achieve such aspects in Korea. To simulate material flow in a subassembly line at a shipyard, the product, process and resources was modeled for the subassembly process which consisted of several sub-processes such as tack welding, piece alignment, tack welding, and robot welding processes. The analysis and modeling were carried out by using the UML(Unified Modeling Language), an object-oriented modeling method as well as IDEF(Integration DEFinition), a functional modeling tool. Initially, the characteristics of the shop resources were analyzed using the shipyard data, and the layout of the subassembly line was designed with the resources. The production process modeling of the subassembly lines was performed using the discrete event simulation method. Using the constructed resource and process model, the productivity and efficiency of the line were investigated. The number of workers and the variations In the resource performance such as that of a new welding robot were examined to simulate the changes in productivity. The bottleneck process floated according to the performance of the new resources. The proposed model was viewed three-dimensionally in a digital environment so that interferences among objects and space allocations for the resources could be easily investigated

• Korean Journal of Computational Design and Engineering
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• v.21 no.2
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• pp.204-214
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• 2016

Shipbuilding process takes a long time for producing final products, and needs many different resources. Because of these characteristics, it has been studied about shipyard simulation and virtual manufacturing that is able to implement the virtual manufacturing process. However, among the previous researches, it requires considerable time and effort to construct simulation model since the systematic methodology has not been used for simulation modeling. Also, reusability of constructed simulation model was low. Therefore, this research defines the method to construct shipyard simulation system using the process-centric simulation modeling methodology and shipyard simulation framework. This paper also validates the utility of this methodology through applying to construct simulation model for the shipyard master plan validation.

• Korean Journal of Computational Design and Engineering
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• v.11 no.1
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• pp.11-19
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• 2006

For several years, a research about the simulation for shipyard and shipbuilding has been performed. This research is based on the concept of PLM (Product Lifecycle Management) and DM (Digital Manufacturing). Global leading companies and research center are trying to get a good position of PLM, especially M&S field. Digital shipbuilding is to computerize shipyard facilities and shipbuilding processes, and to simulate expected scenarios of shipbuilding processes using a computer model in order to resolve a potential problem such as a bottleneck processes, and over loaded resources. In this paper, simulation methodology for shipbuilding is described. In addition, a local and global strategy for the use of simulation methodology is suggested. Finally, case studies about an indoor shop and an outdoor shop are described.

• Journal of Welding and Joining
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• v.20 no.1
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• pp.10-17
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• 2002

• Korean Journal of Computational Design and Engineering
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• v.10 no.3
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• pp.210-216
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• 2005

Digital manufacturing could be very effective in shipbuilding in order to estimate the process time, to improve the operation efficiency, and to prevent bottleneck processes in advance. The subassembly process having done research consists of piece arrangement, tack welding, robot welding, manual welding and so on. The robot welding of them was the focus of the simulation. The analysis and modeling were carried out by using UML (Unified Modeling Language) as well as $IDEF\phi$ (Integration DEFinition). The characteristics of the process resources were analyzed using the shipyard data, and the layout of the subassembly line was designed with the resources. Using the constructed resource and process model, the productivity and efficiency of changed robot welding stage were investigated. It was simulated how much the variations in the resource performance have influence on improvement of productivity. One of the important outputs in this simulation was the cycle time during a certain period's work. The cycle time prediction was also undertaken for the different torch and the different piece arrangement. The proposed model was established three-dimensionally in a digital environment so that interferences among objects and space allocations for the resources could be easily investigated.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.1 s.139
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• pp.64-72
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• 2005

Digital manufacturing is a technology to simulate the real manufacturing process using the virtual model representing the physical schema and the behavior of the real manufacturing system including resources, processes and product information. Therefore, it can optimize the manufacturing system or prevent the bottleneck processes through the simulation before the manufacturing plan is executed. This study presents a method to apply the digital manufacturing technology for the steel cutting process in shipyard. The system modeling of cutting shop is carried out using the IDEF and UML which is a visual modeling language to document the artifacts of a complex system. Also, virtual NC simulators of the cutting machines are constructed to emulate the real operation of cutting machines and NC codes. The simulators are able to verify the cutting shape and estimate the precise cycle time of the planned NC codes. The validity of the virtual model is checked by comparing the real cutting time and shape with the simulated results. It is expected that the virtual NC simulators can be used for accurate estimation of the cutting time and shape in advance of real cutting work.