• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.34 no.4
• /
• pp.179-188
• /
• 2011

This paper outlines a systematic guideline for remanufacturing process using the Failure Mode and Effect Analysis (FMEA) method in order to estimate the reliability and quality of the remanufactured alternator. The method is just a tool to help, but the remanufacturer must determine the optimal remanufacturing process and specific inspection and production that will turn the alternator as-good-as new and place the product into the market with reliability and quality equal to a new product. FMEA is a method that is widely used in industry and has shown its value and effectiveness in the above remanufacturing case study. Actions taken often result in a lower severity, occurrence or detection rating. Redesign may result in lower severity and occurrence ratings while inserting validation controls and maintenance can reduce the detection rating. The revised ratings are recorded with the originals on the FMEA template form. After these corrective actions and revisions have been established, evaluation of the ranks can be repeated, until the redesign and control parameters comply with safety standards.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.9
• /
• pp.50-61
• /
• 2018

A precedent defense project study was carried out in the early stage of the project to support efficient determination of the acquisition method of the determined weapons system. A precedent study in the early stage of the project has been neglected, but lack of performance and increased costs are continuing problems. In a precedent study on a number of items within a limited time frame, expected risks during project implementation were not identified and reduced by failing to review the key review element in depth. Therefore, in this paper, we studied the application of the FTA/FMEA technique used in the system safety analysis process to identify key factors to be considered when carrying out the defense research project. The methodology for the development of the key review items was established through the improvement of the FTA/FMEA technique in order to meet specific conditions and given conditions. Based on the results of this study, we redefined core key factors in the precedent study stage, thereby eliminating unnecessary and anticipated risks that may arise in the future project management aspects of the defense project. It is anticipated that this will reduce costs and time in terms of the lifecycle of the weapon system and promote stable operation of the project through reduction of risk.

• Journal of the Society of Naval Architects of Korea
• /
• v.37 no.3
• /
• pp.78-89
• /
• 2000

The quality of a product/system is getting more important concept nowadays. 'Performance', as one of the quality characteristics, means how well a product carries out its given functions and is the most adjacent characteristics to the customer satisfaction. To an engineer, however, who deals with large structures such as ships, 'Safety' is actually getting more important because of its direct relationship with failures of a product/system itself and human injuries when an accident occurs. In this study, therefore, we consider both performance and safety recognized the most important elements in dealing with structures and present a quality analysis method based on customer requirements by using QFD for performance analysis and FMEA for safety analysis respectively. Applying these methods to the hatchway of a bulk carrier, we could find 8 and 12 important parts based on performance and safety respectively. Among these, only 7 parts were pointed out commonly critical. From these, we can suggest that designers should pay more attention to these 7 parts and thus give a high priority of concerns to them when trying to improve the quality of system.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.33 no.4
• /
• pp.209-217
• /
• 2010

Reliability tools such as QFD and FMEA identify voice of customer related to product design, its use, how failures may occur, the severity of such failures, and the probability of the failure occurring. With these identified items, a development team can focus on the design process and the major issues facing the product in its potential use environment for the customer. The purpose of this research is to develop a reliability estimation process of agricultural machinery components using QFD, FMEA, and field failure data. Based on QFD method, customer requirements, engineering design elements and part characteristics were deployed. Using the field failure data, failures are investigated, and Weibull B10 life are estimated. This estimation process is useful for preparing the design input and planning the durability target.

• Journal of the Korean Society of Safety
• /
• v.28 no.4
• /
• pp.81-90
• /
• 2013

To meet increased demand and lead to execution of successful overseas's plant construction, A prompt System is urgently needed to carries prevention and control of hazards associated with work related tasks and activities. This study is aimed to develop efficient and reliable safety management program to identify control measures for high risk activities by choosing and conducting proper risk assessment methodology that addresses Risk Priority Number(RPN) of adverse effects.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2020.11a
• /
• pp.1097-1100
• /
• 2020

챗봇(Chatbot)은 자연어처리기술 등 인공지능 기술을 기반으로 한 사용자 친화적인 대화 방식 인터페이스를 제공하는 장점이 있어, 금융, 상담, 주문 등 다양한 산업 분야에서 적용되고 있다. 그러나, 챗봇의 응답이 사용자의 정신 모형과 불일치하는 경우, 다음 대화를 이어가는데 어려움을 야기하게 된다. 그러므로, 챗봇의 사용성을 확보하기 위해서는 응답 오류의 제거 또는 완화가 필수적이다. 기존의 챗봇의 사용성 개선과 관련된 연구들은 설문조사와 인터뷰 등 사용성 평가를 통해 상위 수준의 개선 방향만을 제안하고 있다. 따라서, 챗봇 개발 시, 실무자들이 응답 오류의 문제점을 분석하고, 이를 해결하기 위한 구체적인 개선 방안을 제시하는 데 한계가 있었다. 본 논문에서는 FMEA(Failure Modes and Effects Analysis) 기법을 활용해, 응답 오류의 치명도를 파악하고, 치명적인 오류들에 대해서는 FTA(Fault Tree Analysis) 기법을 기반으로 원인 분석을 실시하여 구체적으로 문제를 해결하기 위한 프로세스를 제안한다. 본 프로세스의 효용성을 검증하기 위해 주문 도메인의 챗봇에 적용해 보았다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.10
• /
• pp.68-78
• /
• 2016

Safety is the most important factor for train control systems. Model-based design and safety activities for way-side equipment in train control systems are important factors. Model-based architecture verification was carried out to develop an effective control system, which is represented by model-based failure mode and effects analysis (FMEA). An architecture verification method was created based on FMEA to take advantage of a design model and improve the train safety control system. Case studies were applied to architecture verification scenarios, and the results demonstrate the usability of the method. The improved method is expected to reduce the cost and time in the conceptual design for future development of model-based verification train control systems.

• Journal of the Korea Safety Management & Science
• /
• v.15 no.1
• /
• pp.11-19
• /
• 2013

In modern systems design and development, one of the key issues is considered to be related with how to reflect faithfully the stakeholder requirements including customer requirements therein, thereby successfully implementing the system functions derived from the requirements. On the other hand, the issue of safety management is also becoming greatly important these days, particularly in the operational phase of the systems under development. An approach to safety management can be based on the use of the failure mode effect and analysis (FMEA), which has been a core method adopted in automotive industry to reduce the potential failure. The fact that a successful development of cars needs to consider both the complexity and failure throughout the whole life cycle calls for the necessity of applying the systems engineering (SE) process. To meet such a need, in this paper a method of FMEA is developed based on the SE concept. To do so, a process model is derived first in order to identify the required activities that must be satisfied in automotive design while reducing the possibility of failure. Specifically, the stakeholder requirements were analyzed first to derive a set of functions, which subsequentially leads to the task of identifying necessary HW/SW components. Then the derived functions were allocated to appropriate HW/SW components. During this design process, the traceability between the functions and HW/SW components were generated. The traceability can play a key role when FMEA is performed to predict the potential failure that can be described with the routes from the components through the linked functions. As a case study, the developed process model has been applied in a project carried out in practice. The results turned out to demonstrate the usefulness of the approach.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.7 no.2
• /
• pp.7-13
• /
• 2011

Turbine journal bearings are designed to support the weight of the rotors on a hydrodynamic oil film and to provide dynamic stability to the rotor system. The life time of journal bearings is infinite theoretically because the journal bearings are separated from the shaft journal by oil film. But poor design, assembly, operation and maintenance can cause problems to the journal bearings. The FMEA(Failure Mode and Effects Analysis) results of the journal bearings show that frequent maintenance of the journal bearings can cause failures and reduction of the bearing life. Therefore, the maintenance periods and history of the journal bearings with the bearing FMEA results are reviewed in order to establish the optimized maintenance period of the journal bearing for the nuclear power plants. Consequently it is necessary to maintain a best condition of lubrication system, reject time-based maintenance and perform the condition-based maintenance of journal bearings in order to maintain optimum condition of the journal bearing.

• Journal of the Korean Society for Railway
• /
• v.9 no.6 s.37
• /
• pp.725-731
• /
• 2006

Hot Standby sparing system detecting faults by using software, and being tolerant any faults by using Hardware Redundancy is difficult to perform quantitative reliability prediction and to detect real time faults. Therefore, this paper designs Hot Standby sparing system using hardware basis self checking logic in order to overcome this problem. It also performs failure mode analysis of Hot Standby sparing system with designed self checking logic by using FMEA (Failure Mode Effect Analysis), and identifies reliability assessment of the controller designed by quantifying the numbers of failure development by using FTA (Fault Tree Analysis)