• 시스템엔지니어링학술지
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• 제19권1호
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• pp.29-38
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• 2023

Independent Safety Assessment (ISA) is a third-party assessment that is to confirm that the system satisfies the safety requirements in the defined operational context. The process of this assessment often brings about many complex arguments that should be supported by evidence and justification. The communication between arguments and evidence is of the most importance in the context of safety case. This study illustrates how NOR-STA can be used for ISA process, showing the effective structure of safety compliance. The study outlines the steps to breaks down the top goal into many elements such as arguments, sub-goals, justification, context and assumptions. It concludes that the evidence-based safety conformance process utilizing NOR-STA provides a more effective and systematic representation of the independent safety assessment process in conformance cases.

• Nuclear Engineering and Technology
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• 제49권2호
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• pp.295-305
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• 2017

This paper reviews current status of the unified approach known as integrated safety assessment (ISA), as well as the associated SCAIS (simulation codes system for ISA) computer platform. These constitute a proposal, which is the result of collaborative action among the Nuclear Safety Council (CSN), University of Madrid (UPM), and NFQ Solutions S.L, aiming to allow independent regulatory verification of industry quantitative risk assessments. The content elaborates on discussions of the classical treatment of time in conventional probabilistic safety assessment (PSA) sequences and states important conclusions that can be used to avoid systematic and unacceptable underestimation of the failure exceedance frequencies. The unified ISA method meets this challenge by coupling deterministic and probabilistic mutual influences. The feasibility of the approach is illustrated with some examples of its application to a real size plant.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1669-1679
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• 2010

Related to the on-going "Train Control System Project of Pilot Line Construction for Urban MAGLEV Train", activities by each phase shall be conducted to achieve SIL4 level and obtain safety certification from the Independent Safety Assessment(ISA), based on the IEC standards((IEC 62278/62279 and IEC 62425) for the first time in Korea. This thesis describes the introduction of IEC standards, system assurance activities (such as plan, analysis, test, verification and validation) in compliance with requirements management and project life-cycle and relations with the safety assessment activities; and certification activities (such as document reviews and audits) through system RAMS activities, software quality assurance activities and safety assessment, for the purpose of achieving a successful safety certification at the time of completing the project as system assurance activities including software and safety certification activities in order to acquire the safety certification for train control system which does not exist at all in domestic cases. It is believed that overall system safety assurance activities in this project will contribute to develop more upgraded products of the domestic train control system on the quality and safety point of view, find overseas markets and establish a bridgehead in the future.

• 전기학회논문지P
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• 제63권4호
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• pp.226-235
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• 2014

Nowadays, railroads are considered the most efficient form of mass transportation. Furthermore, it is necessary that railroads be paired with state-of-the-art safety equipment. Unfortunately, it is impossible to prevent 100% of accidents that may be caused by system or human errors. In order to prevent future accidents, RAMS activity and Functional Safety Certification are required for new systems that are under development. In this paper we evaluate the necessity of the application of RAMS and the performance of RAMS in the system development process. We also explore the Safety Evaluation Procedure required for RAMS certification.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1118-1125
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• 2010

This paper presents the methods to acquire the Safety Certificate from Independent Safety Assessment based on the IEC standard62279 which is commonly applied to railway system for Automatic Train Control(ATC) system in accordance with Urban Maglev project. This also shows approach methods and relative activities for project life-cycle to accomplish and ensure the system requirements of ATC system, RAMS and S/W quality activities. Furthermore, the key tasks conducted with ISA are noted in detail. These kind of activities for software quality of ATC system to obtain Safety Certificate could be a CASE model to improve the quality of domestic railway system and products, and also contribute to the growth of railway business and toward the achievement of overseas' railway signaling markets.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.711-716
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• 2011

Ministry of Land, Transportation and Maritime Affairs of Korea has started a research project on verification process and safety assessment of Communication Based Train Control (CBTC) system for metropolitan railroad control as a 3-year project starting from 2010. As a number of companies has made efforts in securing the technologies for domestic production of CBTC systems, the purpose of the project is to develop the specification for interoperability with the considerations for local environments including metropolitan train operations and wireless communications. And the developed systems and the RAMS related outcomes from the participating companies are subject to Independent Safety Assessment (ISA) performed by a foreign specialized agency and the corresponding certificates are to be issued as a part of the project. In this paper, the RAMS management for verification and commercialization of metropolitan railroad CBTC systems has been studied. The study includes response strategy for the requirements of international standards, responsibility and authority of the related institute and the companies, quantitative RAMS objectives, and risk management strategies in project fulfillment.

• 한국철도학회논문집
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• 제13권4호
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• pp.412-418
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• 2010

본 논문에서는 최근 들어 철도신호시스템분야에서 중요한 이슈로 부각되고 있는 소프트웨어 측면에서의 신뢰성과 안전성 수준을 국제규격(IEC 62279)에 부합할 수 있도록 하기 위한 접근방법을 모색하며, 실제 적용사례(국토해양부 및 한국건설교통기술평가원이 주관하는 국가 대형연구개발 실용화 사업인 "도시형 자기부상열차 실용화사업 시범노선 건설 열차제어시스템 구매/설치")를 통하여 현실적이고 접근가능한 구체적인 활동 사항들을 프로젝트 수행과 연관하여 기술한다. 또한 열차제어시스템의 안전성 인증 획득을 위한 소프트웨어를 포함한 시스템 보증활동 및 시스템 보증을 위한 조직체계를 확립하고, 요구사항 관리 및 프로젝트 공정에 따른 절차적 시스템 보증 활동과 안전성평가 활동과의 연관관계, 시스템 전반에 걸친 RAMS 및 소프트웨어 품질보증 활동과 안전성 평가를 통한 인증활동에 대한 부분을 상세 제시하고자 한다. 본 활동을 통하여 지금까지 국제규격에 따른 활동기준에 대해서 모호하거나, 명확하게 정의되지 않은 사항들이 체계적으로 정리될 수 있을 것으로 사료되며, 타 사업 및 국내 철도신호시스템 적용을 위한 소프트웨어 품질 및 안전 무결성 수준 확보에 따른 안전성 확보방안의 구체적인 케이스 모델이 될 것으로 기대된다.