• Industrial Engineering and Management Systems
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• v.9 no.3
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• pp.251-261
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• 2010

This article demonstrated the application of the Fuzzy Data Envelopment Analytical Hierarchy Process (FDEAHP) to evaluate the root causes of critical defect problems occurring in the production of liquid medicine. The methodology of the research began by collecting the defect data by using Check Sheets, and ranking the significant problems by using a Pareto Diagram. Two types of major problems were found to occur, including glass fragments in the medicine and damaged lid threads. The causes of each problem were then analyzed by using Cause and Effect Diagrams. The significant causes were ranked by FDEAHP under three criteria, Severity (S), Occurrence (O) and Detection (D), followed by the framework of the FMEA Technique. Two causes with the highest Final Weight (FW) of each problem were selected to be improved, such as installing auxiliary equipment, using the Poka-Yoke system, setting the scale of the shaft and lathing the bushes of each bottle size. The results demonstrated a reduction in defects from 3.209% to 1.669% and showed that improving a few significant root causes, identified by an experienced decision maker, was sufficient to reduce the defect rate.

• Journal of Korean Society for Quality Management
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• v.44 no.1
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• pp.109-120
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• 2016

Purpose: This study developed a method of determining priorities for evaluating and revising defense standards. Methods: The proposed data integration and refinement methods are used to obtain component reliability information and to determine the frequency of component citation based on Pareto analysis. Based on the reliability information and the frequency of cited components, the target components for quality improvement can be determined and improved using various methods, such as engineering changes, special meetings, additional training, and revising the maintenance manual. Results: Based on the proposed process, we identified components that need to be improved in order to enhance the quality and reliability. Conclusion: Our process will improve the quality and reliability of weapon systems. The proposed process can be adopted for various weapon systems to enhance their quality and reliability, and to reduce military spending.

• Steel and Composite Structures
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• v.51 no.6
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• pp.647-659
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• 2024

Given the increased interest in enhancing structural sustainability, the current study sought to apply multiobjective optimization to a footbridge with a steel-concrete composite I-girder structure. It was considered as objectives minimizing the cost for building the structure, the environmental impact assessed by CO2 emissions, and the vertical accelerations created by human-induced vibrations, with the goal of ensuring pedestrian comfort. Spans ranging from 15 to 25 meters were investigated. The resistance of the slab's concrete, the thickness of the slab, the dimensions of the welded steel I-profile, and the composite beam interaction degree were all evaluated as design variables. The optimization problem was handled using the Multiobjective Harmony Search (MOHS) metaheuristic algorithm. The optimization results were used to generate a Pareto front for each span, allowing us to assess the correlations between different objectives. By evaluating the values of design variables in relation to different levels of pedestrian comfort, it was identified optimal values that can be employed as a starting point in predimensioning of the type of structure analyzed. Based on the findings analysis, it is possible to highlight the relationship between the structure's cost and CO2 emission objectives, indicating that cost-effective solutions are also environmentally efficient. Pedestrian comfort improvement is especially feasible in smaller spans and from a medium to a maximum level of comfort, but it becomes expensive for larger spans or for increasing comfort from minimum to medium level.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.12 no.20
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• pp.123-138
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• 1989

The primary objective of the agency research in the game theory lives in the maintenance of Pareto is optimal condition for the optimal incentive contract. The basic concepts which are related to this objective are reviewed in connection with the general assumptions to model it, the moral hazard and adverse selection which arised from the information asymmetry, and finally the problem of risk distribution. The demand for auditing and the role of auditor have been addressed by ASOBAC. Issues which an auditor is explicitly introduced in a principal-agent framework have been addressed in this paper. These issues must be confronted to appropriately with the auditor, and to achieve an adequate understanding of optimal confronting arrangement with the auditor. The first step in introducing an auditor into this analysis is to examine the game-theoretic foundation of such a expended agency model. The Mathematical program formulated may not yield solution that are resonable. This arises because the program may call for the auditor and manager to play dominated Nash equilibra in some subgame. The nontrivial natures of the subgame implies that randomized strategies by the auditor and manager nay be of crucial importance. The possibilities for overcoming the randomized strategy problem were suggested; change the rule of the game and or impose covexity condition. The former seems unjustifiable in on auditing context, and the latter promising but difficult to achieve. The discussion ended with an extension of the revelation principle to the owner manager-auditor game, assuming strategies. An examination of the restriction and improvement direction of the basic concept of agency theory was addressed in the later part of this paper. Many important aspects of auditor incentives are inherently multiple-agent, multiple-period, multiple-objectine, phenomena and require further analyses and researches.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.321-326
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• 2008

The software defects that are not found in the course of a project frequently appear during the conduct of the maintenance procedure after the complete development of the software. As the frequency of surfacing of defects during the maintenance procedure increases, the cost likewise increases, and the quality and customer reliability decreases. The defect rate will go down only if cause analysis and process improvement are constantly performed. This study embodies the defect tracking system (DTS) by considering the Pareto principle: that most defects are repetitions of defects that have previously occurred. Based on the records of previously occurring defects found during the conduct of a maintenance procedure, DTS tracks the causes of the software defects and provides the developer, operator, and maintenance engineer with the basic data for the improvement of the software concerned so that the defect will no longer be manifested or repeated. The basic function of DTS is to analyze the defect type, provide the measurement index for it, and aggregate the program defect type. Doing these will pave the way for the full correction of all the defects of a software as it will enable the defect correction team to check the measured defect type. When DTS was applied in the software configuration management system of the W company, around 65% of all its software defects were corrected.