• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.20-37
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• 2020

In this paper, we propose a simulation method based on backward simulation and process-oriented simulation to take into account the characteristics of shipbuilding production, which is an order-based industry with a job shop production environment. The shipyard production planning process was investigated to analyze the detailed process, variables and constraints of mid-term production planning. Backward and process-centric simulation methods were applied to the mid-term production planning process and an improved planning process, which considers the shipbuilding characteristics, was proposed. Based on the problem defined by applying backward process-centric simulation, a system which can conduct Discrete Event Simulation (DES) was developed. The developed mid-term planning system can be linked with the existing shipyard Advanced Planning System (APS). Verification of the system was performed with the actual shipyard mid-term production data for the four ships corresponding to a one-year period.

• 한국정밀공학회지
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• 제15권3호
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• pp.82-87
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• 1998

In order to provide a manufacturing system with efficiency and flexibility to cope with the changes in shop floor status, the integration of process planning and operations scheduling is required. In this paper, an integrated system of process planning and operations scheduling based on the concept of process net model and genetic algorithm is suggested. The process net model includes the alternative process plans. The integrated system is applied for prismatic parts.

• International Journal of Precision Engineering and Manufacturing
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• 제2권3호
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• pp.69-78
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• 2001

This paper presents a process and operation planning system and an NC code post-processor for effective machining of press dies for production of cars. Based on the machining feature, major parts of press dies are categorized into 15 groups and a standard process plan is defined for each group. The standard process plan consists of a series of processes where a process is defined as a group of operations that can be done with one setup. Details such as cutting tools, cutting conditions, and tool paths are decided at the operation planning stage. At the final stage of process and operation planning, the NC code post-processor adjusts feedrates along the tool path to reduce machining time while maintaining the quality. The adjustment rule is selected based on the machining load estimated by virtual machining.

• 한국군사과학기술학회지
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• 제10권3호
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• pp.100-108
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• 2007

The purpose of the research is to propose an integrated project planning process and its implementation method. Although there is increasing interest in the application of the Earned Value Management(EVM) method in the project management area, the progress and maturity of the technical performance have not been included in assessing the Earned Value. The main concept of the planning process is to use cost, schedule, as well as the technical performance in the assessment of the Earned Value Management for Military R&D project management practices. The resulting process can enhance the efficiency of the project work by eliminating the currently duplicated activities between traditional project planning process and the newly implemented Earned Value Management process and by shortening the early planning process duration of projects adopting EVM practices.

• 한국CDE학회논문집
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• 제14권1호
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• pp.60-68
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• 2009

Because of the reduced product life-cycle, industries are making an effort to bring down the process planning time. In the traditional approach, we have to analyze established process planning, then design the time chart based on process information and drawing the formal time chart such as SOP(sequence of operation). Thereafter, it will be converted to PLC code that is a time consuming and redundant job. Similarly, Industrial automated process uses PLC Code to control the factory; however, control information and control code(PLC code) are difficult to understand. Hence, industries prefer writing new control code instead of using the existing one. It shows the lack of information reusability in the existing process planning. As a result, to reduce this redundancy and lack of reusability, we propose SOS-Net modeling method. Unlike past stabilized process planning that is rigid to any change; our proposed SOS-Net modeling method is more adaptable to the new changes. The SOS-Net model is easy to understand and easy to convert into PLC Code accordingly. Therefore, we can easily modify the control information and reuse it for new process planning. The proposed model plays an intermediary role between process planning and PLC code generation. It can reduce the process planning and implementation time as well as cost.

• 한국정밀공학회지
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• 제15권11호
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• pp.46-57
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• 1998

Even though there are some studies on the deep drawing process and process planning, little study has been done on the methodology of process planning of secondary operations of deep drawing such as 'piercins'. In this paper, first, we systematized the methodology of the process planning of secondary operations on axisymmetric cup. Second we described the development of the expert system for their CAPP For these studies, we extracted the knowledge of their process planning from experts and analysed and systemized them. To develop the expert system, rule-based reasoning paradigm is used. The shape information of manufacturing features of secondary operations are manually input to the system through SUI. The process planning results are automatically connected to AutoCAD. We believe that the systematized process knowledge and the development of the expert system for its CAPP could give lots of aids to the associated field.

• International Journal of Automotive Technology
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• 제7권2호
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• pp.217-226
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• 2006

To maintain competitiveness in the modern automotive market, it is important to carry out process planning concurrently with new car development processes. Process planners need to make decisions concurrently and collaboratively in order to reduce manufacturing preparation time for developing a new car. Automated generation of a simulation model by using the integrated process plan database can reduce time consumed for carrying out a simulation and allow a consistent model to be used throughout. In this research, we developed a web-based system for concurrent and collaborative process planning and flow analysis for an automotive general assembly using web, database, and simulation technology. A single integrated database is designed to automatically generate simulation models from process plans without having to rework the data. This system enables process planners to evaluate their decisions quickly, considering various factors, and easily share their opinions with others. By using this collaborative system, time and cost put into the assembly process planning can be reduced and the reliability of the process plan would be improved.

• 산업공학
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• 제16권3호
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• pp.375-381
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• 2003

To ensure competitiveness in the modern automotive market, process planning should be performed concurrently with new car developments. In automotive general assembly shops, thus, new business workflows and supporting environments are inevitable to reduce the manufacturing preparation time in developing a new car in the manner of concurrent and collaborative engineering. Since complete process planning for a whole general assembly system is a huge and complex job, several process planners should execute their planning jobs and share information. Therefore, each planner should provide others with his/her results with continuous on-line communication and cooperation. In this research, a web-based system for concurrent and collaborative process planning for automotive general assembly is developed. By using this system, savings in time and cost of assembly process planning are possible, and the reliability of the planning result is improved.

• 대한조선학회논문집
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• 제45권5호
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• pp.547-553
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• 2008

Multi Progress Planning System problem in a multi-stage manufacturing system have a complexity and peculiarity different from other kinds of production system. World leading company has invested much cost and effort into a Real-Time Planning System and intelligent manufacturing field to obtain their own competitiveness. Especially Real-Time Planning System for ship production process as a part of intelligence for a shipyard. Real-Time Planning System, simulation based system, or virtual manufacturing system is an approach to achieve a such goal. It is expected that the Real-Time Planning System will contribute to the improvement of the productivity in working process at a shipyard. Also, This Real-Time Planning System will optimize the entire shipbuilding process in a multi progress planning environment for the delivery.

• 한국정밀공학회지
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• 제17권5호
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• pp.108-115
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• 2000

This paper presents a variant type process planning system for machining of dies for auto-body production. Through the analysis of dies and their manufacturing processes, the authors categorized the press dies into 15 groups according to the similarity of machining features. After critically reviewing current manufacturing procedures, a standard process plan was defined for each group. The authors present MP3D the process planning system built on the standard process plan database, and show how they apply it at the die manufacturing plant of an automobile company. MP3D is expected to reduce major losses in machining such as reworking caused by mistakenly uncut features and eventually to help to accumulate the knowledge of operators. The operation sheet MP3D produces is also used in monitoring the progress of manufacturing of dies. This paper explains the whole development cycle of a process planning system from process analysis to application so that it can help readers to develop and apply a process planning system to their machine shops.