• 산업경영시스템학회지
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• 제22권51호
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• pp.63-72
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• 1999

Many firms have applied flexible manufacturing systems as a means of increasing productivity, profitability, and quality. Therefore, the purpose of this paper is to develop the more efficient justification model through an analytical scoring model with the quantitative factors, flexibility factors, and safety factors under uncertainty. In this paper, the three factors for properly comparing and evaluating of flexible manufacturing systems are presented. Especially, this paper has emphasized the flexibility and safety factor; the one consists of organization assessment, process treatment function, products and products quantity, useful life assesment, and software function, the other presents risk assesment, Y2K problem, safety device analysis, total productive management system, safety management. Finally, a normalized scoring model by the new flexibility and safety factors can be used in real fields for flexible manufacturing systems project selection under uncertainty.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1336-1342
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• 2022

Risk-informed safety classification of structures, systems and components (SSCs) is very important for ensuring the safety and economic efficiency of nuclear power plants (NPPs). However, previous methods for safety classification of SSCs do not take the plant operating modes or the operational process of SSCs into consideration, thus cannot concentrate on the safety and economic efficiency accurately. In this contribution, a new method for safety classification of SSCs based on the categorization of plant operating modes is proposed, which considers the NPPs operating history to improve the economic efficiencies while maintaining the safety. According to the time duration of plant configurations in plant operating modes, average importances of SSCs are accessed for an NPP considering the operational process, and then safety classification of SSCs is performed for plant operating modes. The correctness and effectiveness of the proposed method is demonstrated by application in an NPP's safety classification of SSCs.

• Journal of Ship and Ocean Technology
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• 제4권4호
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• pp.1-18
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• 2000

The paper describes a formalisation of a Design for Safety methodology in an integrated envi-ronment, outlines early developments of a software tool, and presents the results of an appli-cation of the methodology to a case study. The approach adopted attempts link safety per-formance prediction through the utilisation of appropriate technical tools, safety assessment deriving from risk-based methodologies and disparate design activities and issues. Black-board systems have been utilised as the platform in the development of the integrated design environment, allowing safety assessment to become an integral part of the design process. Finally, the case study addresses the application of the developed methodology to three dif-ferent arrangements of a conventional passenger Ro-Ro vessel, with the aim to demonstrate the validity of the process and methodology adopted. The findings are presented and dis-cussed, and recommendations given for the way forward.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권2호
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• pp.92-99
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• 2004

This paper intends to provide practical safety analysis methods and the criteria for method selections. A careful choice of safety analysis techniques will enhance the efficiency of the safety case process. A couple of recommendations are provided from practical experience.

• 대한안전경영과학회지
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• 제16권4호
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• pp.81-90
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• 2014

Modern systems can be characterized by ever-increasing complexity of both the functionality and system scale. Thus, due to the complexity the chances of accidents resulting from systems failure can then be growing. Even worse is that those accidents could result in disastrous damage to the human being and properties as well. Therefore, the need for the developed systems to be assured with systems safety is apparent in a variety of industries such as rail, automobiles, airplanes, ships, oil refinery, chemical production plants, and so on. To this end, in the industry an appropriate safety standard has been published for its own safety-assured products. One of the core activities included in the most safety standards is hazard analysis. A conventional approach to hazard analysis seems to depend upon the scenarios derived from the ones used previously in similar systems or based on former experience. The objective of this paper is to study an improved process for scenario-based hazard analysis. To achieve the goal, the top-level safety requirements have first been reflected in the scenarios. By analyzing and using them, the result has then lead to the development of safety-assured systems. The method of modeling and simulation has been adopted in the generation and verification of scenarios to check whether the safety requirements are reflected properly in the scenarios. Application of the study result in the case of rail safety assurance has also been discussed.

• 대한안전경영과학회지
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• 제9권6호
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• pp.9-17
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• 2007

This article addresses the question of how the operational architecture for a railway safety information system should be developed. A successful railway safety information system can be developed by fully reflecting the business process and needs at the enterprise level. To date, there has been minimal research effort towards the development of the operational architecture for a railway safety information system. To this end, a variety of enterprise architectures have been studied so far. In this paper, as an important guideline, DoDAF (Architecture Framework) is selected to be used in developing a railway safety information system. In particular, we propose a method to implement the operational architecture based on DoDAF.

• 대한안전경영과학회지
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• 제13권4호
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• pp.71-79
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• 2011

The work environment of locomotive cabs has long been an important issue in the design of railload systems since it is quite critical in terms of system's operational safety. It is getting more attention as the running speed of the trains goes up these days. To this end, this paper describes how to systematically construct a DB for the requirements set in the course of the improvement process for the aforementioned cab work environment. As a solution approach, we have adopted the requirement architecture concept to cover the whole activities required to do such as in requirements generation, DB construction, change management, and traceability management. Specifically, based on the requirement architecture framework a requirement process to collect requirements for improvement is discussed, and the guide lines are suggested for verification and validation of the developed requirements. In addition, a base schema and requirements templates are developed, which will be used in generating requirements and constructing a DB. Finally, it is demonstrated how the requirements DB for locomotive cabs can be constructed using a computer-aided tool in an integrated fashion.

• 한국정밀공학회지
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• 제26권3호
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• pp.88-97
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• 2009

The vacuum die casting techniques can diminish the porosity of products and provide better surface appearance by the ordinary high pressure die casting process. The vacuum system can also reduce the cold laps in the die casting process and minimize the overflow pockets of the die. The vacuum system does not need high pressures to die cast compared to the ordinary die casting process, and so enables die casting of large parts for a given machine size. Parts made by the vacuum system have higher strength and more elongation than parts made by the ordinary die casting systems. In this paper, we designed and produced the Magnesium seat frames using the vacuum die casting processes. The new Magnesium seat frame was designed to satisfy safety regulations. Some safety test procedures of the seat frame were simulated by the finite element method. We obtained 10% weight reduction by design modification of seat frames compared to the current model. Flow simulations were carried out to minimize the trial and error in producing the parts. The die casted parts using vacuum systems resulted in better mechanical characteristics and no defects compared to those without vacuum systems.

• 대한안전경영과학회지
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• 제9권6호
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• pp.39-46
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• 2007

In this paper we discuss the problems related with the existing electrical safety system that is influenced by all the socio-technical factors including the electrical safety law, government organizations, and their practicing rules and regulations. Sometimes intangible practices also affect the safety issues. It is our intention to incorporate all those factors effectively and systematically in improving the electrical safety system. Since, the problem in nature is so complex, an approach based on the systems engineering (SE) method could be a good candidate. Specifically, as a first step of the SE process we performed the requirements analysis of all the factors mentioned above and some recommendations from the experts in the field. In the work environment utilizing a computer-aided SE tool, the requirements are verified and managed efficiently although the data base is complicated in general in tracking the changes. Next, by analyzing the verified requirements, a functional architecture is developed to achieve an improved electrical safety system. We also did the reverse engineering of the existing electrical safety system to explore potential problems there. The result can also help improve the existing one. Overall, a systematic approach to constructing electrical safety system based on SE is proposed for the first time in this paper. Note that the method described here can be adopted in the study of other safety systems.

• 대한인간공학회지
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• 제27권2호
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• pp.15-24
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• 2008

As users increasingly recognize the importance of safety and the Product Liability comes into effect, a company should take responsibility of protecting the users who use its product. In order to produce a safe product and satisfy the needs of users, it is critical for develope opriately and understand the characteristics of the product accurately. Furthermore, a safe product can be realized by considering a safety level of the product in a whole product development process. However, in general, product development projects hardly evaluate the safety of a product in the product planning step. In addition, most of safety evaluation methods which are applied in the product planning step have a tendency to be qualitative because a detailed product design step. Therefore, this research aims at enhancing the performance of the safety evaluation process by applying quantitative methods such as 'AHP' and 'Fuzzy'. AHP can help analysts derive the weight of safety factors. Fuzzy is applied to evaluate the degree of safety of product elements in this paper. The proposed method will be able to improve the safety level of a product by using the quantitative methods in the product planning step.