• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.55
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• pp.51-71
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• 2000

A case of company manufacturing industrial valves is studied. To survive the fierce competition in the low-volume, high-complexity production environment, the company needs accurate information on the cost of its products. Current cost accounting system which allocates production costs based on the weights of intermediates and final products cannot provide accurate cost information that managers really need. Data on the company's cost structure and production processes were reviewed and managers were interviewed before problems with the current costing system were identified. Activity-based costing (ABC) system as well as an improved traditional costing system is considered to replace the current system. A prototype of ABC system is developed to better represent the relationships among the cost drivers, activities, and products.

• IE interfaces
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• v.16 no.spc
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• pp.39-44
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• 2003

As one of many design variables, the role of dimension tolerances is to restrict the amount of size variation in a manufactured feature while ensuring functionality. In this study, a nonlinear integer model has been modeled to allocate the optimal tolerance to each individual feature at a minimum manufacturing cost. While a normal distribution determines statistically worst tolerances with its symmetrical property in many previous tolerance allocation studies, a asymmetrical distribution is more realistic because its mean is not always coincident with a process center. A nonlinear integer model is modeled to allocate the optimal tolerance to a feature based on a beta distribution at a minimum total cost. The total cost as a function of tolerances is defined by machining cost and quality loss. After the convexity of manufacturing cost is checked by the Hessian matrix, the model is solved by the Complex Method. Finally, a numerical example is presented demonstrating successful model implementation for a nonlinear design case.

• IE interfaces
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• v.21 no.1
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• pp.131-140
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• 2008

To shorten product development time and cost, integrated information managements of product, manufacturing process and resource are essential. In the area of material addressing, process engineers should make their decisions in the manner of collaborative engineering in order to reduce the manufacturing preparation time and cost in the product development and production. A digital virtual factory which is an united digital model of entire factory could be very useful for these areas. In this paper, the digital virtual factory is constructed and used for material addressing and analysis of an automotive general assembly shop. We developed the material addressing system for automotive general assembly shops using digital virtual factory models and nesting algorithms, and applied it to realistic problems of a Korean automotive company as an convenient and effective way of material addressing.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.850-853
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• 2004

The development of 3D CAM system for the manufacturing of end mills becomes a key approach to save the time and reduce cost for end mills manufacturing. This paper presents the calculation and simulation of end mill tools CNC machining bases on 5-axes CNC grinding machine tool. In this study describes the process of generation and simulation of grinding point data between the tool and the grinding wheels through the machined time. Depend on input data of end mill geometry, wheels geometry, wheel setting, machine setting the end mill configuration and NC code for machining will be generated and visualized in 3 dimension before machining. The 3D visualizations of end mill manufacturing was generated by using OpenGL in C++. The development software was designed by using Microsoft Visual C++, which has many advantages for users, saving time and reducing manufacturing cost.

• Transactions of Materials Processing
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• v.17 no.5
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• pp.350-355
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• 2008

Currently, in the automotive industry, the efforts to reduce the manufacturing cost by changing the manufacturing process are continually performed. In this paper, we proposed a new manufacturing process, the roll bending process of a ring plate of automotive fuel tank instead of conventional press blanking process to reduce material loss and manufacturing cost. Finite element analysis was used to optimize the roll bending process to assure rectangular cross-section of the ring plate. Also, spring-back analysis after the roll bending process was performed and dimension of the bending die considering spring-back was analyzed. Finally, we verified a possibility for realization of the proposed method with prototypes.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.3
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• pp.413-426
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• 1996

Modern society, as a result of high industrial technology, is characterized by a series of mass production, moss consumption and mass disposal. As the mass disposal is known as the major culprit of destroying ecological system of our environment, human prosperity is in turn threatened by this indiscrete activities. Under current industrial technology which pursuit maximum profit, environmental problems could not be solved. This paper proposes recycle manufacturing systems of assemble products as a measure of current non-recycle manufacturing systems. Products are also composed of a number of ports. All parts are represented by a function of time cost performance variable as reuse level. We develop on information systems which give all the information on reused and recycled parts. We try to implement this result on a real fields. We confide ourselves to the contribution to on effective solution of environmental problems and to give profit to assembly manufacturing and consumers.

• Journal of the Korea Safety Management & Science
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• v.5 no.4
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• pp.169-185
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• 2003

Recently many researchers contributed to the understanding of Quality Control System, but the use of economics in the design of quality assurance system is limited in treatment of the relationship between the average incoming quality level (or average process quality level) of the incoming lot and the average outgoing quality level of this lot. In this study, a traditional concept of sampling inspection plan for the quality assurance system is extended to a consideration of economic aspects in total production system by representing and analyzing the effects between proceeding and succeeding production process including inspection process. This approach recognizes that the decision at each manufacturing process (or assembly process), is to be determined not only by the cost and the average outgoing quality level of that process, but also by the input parameters of the cost and the incoming quality to the succeeding process. By analyzing the effects of the average incoming and outgoing quality, manufacturing or assembly process quality level and sampling inspection plan on the production system, mathematical models and solution technique to minimize the total production cost for a general product manufacturing system with specified average outgoing quality limit are suggested.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.5
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• pp.294-302
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• 2021

In this study, the 3D printing technique called design for additive manufacturing (DfAM) that is widely used in various industries was applied to marine leisure ships of equipment. The DfAM for the stanchion for crew safety was applied to the equipment used in an actual recreational craft. As design constraints, the design alternatives were not to exceed the safety and weight of the existing stainless steel material, which were reviewed, and the production of a low-cost FFF-type 3D printing method that can be used even in small shipyards was considered. Until now, additive manufacturing has been used for manufacturing only prototypes owing to its limitations of high manufacturing cost and low strength; however, in this study, it was applied to the mass production process to replace existing products. Thus, a design was developed with low manufacturing cost, adequate performance maintenance, and increased design freedom, and the optimal design was derived via structural analysis comparisons for each design alternative. In addition, a life-cycle assessment based on the ISO 1404X was conducted to develop sustainable products. Through this study, the effectiveness of additive manufacturing was examined for future applications in the shipbuilding industry.

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.139-145
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• 2015

Modular construction is combined with manufacturing production process and conventional construction industry technique. Considering characteristic of modular construction production process, manufacturing facilities require indirect costs for utilities, equipment, and overall maintenance, which can affect modular units pricing. However, current modular construction cost classification is inadvertent to reflect the manufacturing overhead costs, because it is generally added as a percentage to sum of labor, material and equipment as it called in single cost pool used. This process is easy to estimate the total construction cost at the project starting points, but it brings on misunderstanding of project profit estimations by "cross subsidization phenomenon". To prevent this situation, in this research aims to provide modular construction overhead cost handling process at the detailed indirect cost calculation for manufacturing stage using Activity-Based Costing as one of the powerful method for overhead costs estimation and allocation. Using this research results, modular construction cost estimators have more detailed cost information of modular units and prevent to misallocate indirect costs. Also, it can be utilized to aid the understanding of the company's profit structure.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.475-478
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• 2004

Tool costs can comprise a significant part of the total operating costs of Flexible Manufacturing Systems. We address the problem of determining the optimal processing times of individual operations and routing mix in FMSs with multiple routes for each part type in order to minimize tool cost, subject to meeting a throughput constraint for each part type. The problem is formulated as a nonlinear program superimposed on a closed queueing network of the FMSs under consideration. Numerical examples reveal the potential of our approach for significant saving in tool costs.