• 한국군사과학기술학회지
• /
• 제10권1호
• /
• pp.55-69
• /
• 2007

The paper provides the approach to apply formal methods to the development and certification criteria of defense safety/security-critical software. RTCA/DO-178B is recognized as a do facto international standard for airworthiness certification but lack of concrete activities and vagueness of verification/certification criteria have been criticized. In the case of MoD Def Stan 00-55, the guidelines based on formal methods are concrete enough and structured for the defense safety-related software. Also Common Criteria Evaluation Assurance Level includes the strict requirements of formal methods for the certification of high-level security software. By analyzing the problems of DO-178B and comparing it with MoD Def Stan 00-55 and Common Criteria, we identity the important issues In safety and security space. And considering the identified issues, we carry out merging of DO-178B and CC EAL7 on the basis of formal methods. Also the actual case studies for formal methods applications are shown with respect to the verification and reuse of software components.

• Nuclear Engineering and Technology
• /
• 제27권3호
• /
• pp.385-392
• /
• 1995

월성원자력 2, 3, 4호기 safety-critical 소프트웨어에 대한 규제 기관의 요구사항을 만족시키기 위하여 소프트웨어 엔지니어링 절차가 개발되었다. 본 논문에서는 그 중에서 검증시험절차에 대하여 기술하였는데, 검증시험이란 설계그룹에서 개발된 소프트웨어가 독립된 기능그룹에서 부여한 요구사항을 모두 만족하는지를 확인하는 것이다. 이 검증시험을 수행하기 위하여 시험설비와 시험용 소프트웨어가 개발되었으며, 검증시험은 기능시험, 성능시험 및 자기점검시험 등으로 구성되었다. 시험결과를 분석하여, 불만족한 경우는 설계그룹에 통보되어 소프트웨어가 수정되었고, 최종결과는 보고서로 작성되어 규제기관에 제출될 것이다. 개발된 검증시험 방법과 절차는 효율적이고 성공적이었으며, 시험결과는 소프트웨어가 기능사양서를 충분히 만족시킨다는 것을 성공적으로 검증함을 보여주었다. 본 시험방법은 다른 safety-critical 소프트웨어 검증에도 적용될 수 있을 것이다.

• 한국품질경영학회:학술대회논문집
• /
• 한국품질경영학회 2004년도 품질경영모델을 통한 가치 창출
• /
• pp.114-119
• /
• 2004

Software verification and validation(V&V) is a means to develop high-quality software and assure safety and reliability for software. Also, we can achieve the desired software quality through systematic V&V activities. The software to be applied safety critical system like nuclear power plants is required to setup the V&V methodology that comply with licensing requirements for nuclear power plants and should be performed V&V activities according to it. In this paper, we classified safety-critical, safety-related and non-safety for software according to safety function to be peformed and define V&V activities to be applied software grade. Also, we defined V&V activities, procedures and documentation for each phase of software development life cycle and showed techniques and management to perform V&V. Finally, we propose the V&V framework to be applied software development of SMART(System-integrated Modular Advanced ReacTor) MMIS (Man-Machine Interface System) and to comply with domestic licensing requirements.

• Nuclear Engineering and Technology
• /
• 제41권1호
• /
• pp.91-98
• /
• 2009

The "3+3 Process" for safety critical software for nuclear power plants' I&C (Instrumentation and Control system) has been developed in this work. The main idea of the "3+3 Process" is both to simplify the software development and safety analysis in three steps to fulfill the requirements of a software safety plan [1]. The "3-Step" software development process consists of formal modeling and simulation, automated code generation and coverage analysis between the model and the generated source codes. The "3-Step" safety analysis consists of HAZOP (hazard and operability analysis), FTA (fault tree analysis), and DV (design validation). Put together, these steps are called the "3+3 Process". This scheme of development and safety analysis minimizes the V&V work while increasing the safety and reliability of the software product. For assessment of this process, validation has been done through prototyping of the SDS (safety shut-down system) #1 for PHWR (Pressurized Heavy Water Reactor).

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 춘계학술대회 논문집
• /
• pp.987-992
• /
• 2007

Safety critical systems are those in which a failure can have serious and irreversible consequences. Nowadays digital technology has been rapidly applied to critical system such as railways, airplanes, nuclear power plants, vehicles. The main difference between analog system and digital system is that the software is the key component of the digital system. The digital system performs more varying and highly complex functions efficiently compared to the existing analog system because software can be flexibly designed and implemented. The flexible design make it difficult to predict the software failures. This paper reviews safety standard and criteria for safety critical system such as railway system and introduces the framework for the software lifecycle. The licensing procedure for the railway software is also reviewed.

• Nuclear Engineering and Technology
• /
• 제38권3호
• /
• pp.259-276
• /
• 2006

As the use of digital systems becomes more prevalent, adequate techniques for software specification and analysis have become increasingly important in nuclear power plant (NPP) safety-critical systems. Additionally, the importance of software verification and validation (V&V) based on adequate specification has received greater emphasis in view of improving software quality. For thorough V&V of safety-critical systems, V&V should be performed throughout the software lifecycle. However, systematic V&V is difficult as it involves many manual-oriented tasks. Tool support is needed in order to more conveniently perform software V&V. In response, we developed four kinds of computer aided software engineering (CASE) tools to support system specification for a formal-based analysis according to the software lifecycle. In this work, we achieved optimized integration of each tool. The toolset, NuSEE, is an integrated environment for software specification and V&V for PLC based safety-critical systems. In accordance with the software lifecycle, NuSEE consists of NuSISRT for the concept phase, NuSRS for the requirements phase, NuSDS for the design phase and NuSCM for configuration management. It is believed that after further development our integrated environment will be a unique and promising software specification and analysis toolset that will support the entire software lifecycle for the development of PLC based NPP safety-critical systems.

• Journal of Multimedia Information System
• /
• 제2권2호
• /
• pp.241-248
• /
• 2015

The safety-critical software in healthcare systems needs more and more perceptive excess among human observation and computer support. It is a challenging conversion that we are fronting in confirming security in healthcare systems. Held in the center are the patients-the most important receivers of care. Patient injuries and fatalities connected to health information technologies commonly show up in the news, contrasted with tales of how health experts are being provided financial motivation to approve the products that may be generating damage. Those events are unbelievable and terrifying, however they emphasize on a crucial issue and understanding that we have to be more careful for the safety and protection of our patients.

• Nuclear Engineering and Technology
• /
• 제52권7호
• /
• pp.1462-1470
• /
• 2020

Reliability in safety-critical systems and equipment is of vital importance, so the probabilistic safety assessment (PSA) has been widely used for many years in the nuclear industry to address reliability in a quantitative manner. As many nuclear power plants (NPPs) become digitalized, evaluating the reliability of safety-critical software has become an emerging issue. Due to a lack of available methods, in many conventional PSA models only hardware reliability is addressed with the assumption that software reliability is perfect or very high compared to hardware reliability. This study focused on developing a new method of safety-critical software reliability quantification, derived from hardware-software integrated environment testing. Since the complexity of hardware and software interaction makes the possible number of test cases for exhaustive testing well beyond a practically achievable range, an importance-oriented testing method that assures the most efficient test coverage was developed. Application to the test of an actual NPP reactor protection system demonstrated the applicability of the developed method and provided insight into complex software-based system reliability.

• 한국항공우주학회지
• /
• 제40권6호
• /
• pp.548-554
• /
• 2012

항공기 비행조종컴퓨터 탑재 소프트웨어는 항공기의 손실뿐만 아니라 조종사의 생명에도 직결되는 비행안전 필수 소프트웨어로서 정확성과 무결성을 입증하기 위한 검증 및 확인(Verification & Validation)이 요구된다. 특히 비행안전 필수 소프트웨어는 검증을 위해 통합시험 단계에서 실제 환경과 유사한 운용 환경에 노출하여 소프트웨어 내부 상태를 실시간으로 모니터링하기 위한 환경이 요구된다. 본 논문에서는 표준 디버깅 인터페이스인 NEXUS 5001을 이용한 비행안전 필수 소프트웨어의 검증환경 개발에 대하여 기술하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.201-203
• /
• 2007

Safety critical systems are those in which a failure can have serious and irreversible consequences. Nowadays digital technology has been rapidly applied to critical system such as railways, airplanes, nuclear power plants, vehicles. The main difference between analog system and digital system is that the software is the key component of the digital system. The digital system performs more varying and highly complex functions efficiently compared to the existing analog system because software can be flexibly designed and implemented. The flexible design make it difficult to predict the software failures. This paper reviews safety standard and criteria for safety critical system such as railway system and suggests software development methodology for more detail description.