• KIPS Transactions on Software and Data Engineering
• /
• v.2 no.10
• /
• pp.661-668
• /
• 2013

A safety critical system is a system that leads to injury of people, damage of property and environment due to functional failures or occurrence of undesired condition. Therefore, to ensure the safety of a system, system engineers should consider the inherent hazards of the system at design phase of the system development, and also should design the prevention actions to minimize damage when an accident occurred. The objective of these actions is preventing the serious damage from accidents that can occur due to unforeseen circumstance. Recently, many studies have been performed to identify and analyze their hazards at design phase of safety critical systems. This paper suggests a safety analysis technique for analyzing the collision among those prevention actions to reduce accident and its effect by the collision of these actions that did not mentioned in previous studies. Through the proposed technique, it would improve robustness of safety and would help the design of prevention actions into system for the occurrence of accidents.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10a
• /
• pp.486-488
• /
• 2000

본 연구는 정형기법을 사용하여 Safety-Critical System의 개발 방법론을 제시한다. Safety-Critical System의 전체적인 개발 과정을 제시하고 Safety-Critical System 중의 하나인 원자력 발전소 시스템 중 Reactor Protection System(RPS)을 정형 명세(Formal Specification)하고 정형 검증(Formal Verification)하는 과정과 그에 따른 각 과정의 Compliance를 확인하는 예를 든다. 여기서 정형 명세에는 Software Cost Reduction(SCR)이하는 도구가 사용되었고, 정형 검증에는 SPIN이, Compliance를 확인하는 데에는 Prototype Verification System(PVS)를 사용하였다.

• Journal of the Korea Safety Management & Science
• /
• v.11 no.3
• /
• pp.19-26
• /
• 2009

It is becoming more and more important to develop safety-critical systems with special attention. Examples of the safety-critical systems include the mass transportation systems such as high speed trains, airplanes, ships and so forth. Safety critical issues can also exist in the development of atomic power plants that are attracting a great deal of attention recently as oil prices are sky-rocketing. Note that the safety-critical systems are in general large-scale and very complex for which case the effects of adopting the systems engineering (SE) approach has been quite phenomenal. Furthermore, safety-critical requirements should necessarily be realized in the design phase and be effectively maintained thereafter. In light of these comments, we have considered our approach to developing safety-critical systems to be based on the method combining the systems engineering and safety management processes. To do so, we have developed a design environment by constructing a whole life cycle model in two steps. In the first step, the integrated process model was developed by integrating the SE (ISO/IEC 15283) and systems safety (e.g., hazard analysis) activities and implemented in a computer-aided SE tool environment. The model was represented by three hierarchical levels: the life-cycle level, the process level, and the activity level. As a result, one can see from the model when and how the required SE and safety processes have to be carried out concurrently and iterately. Finally, the design environment was verified by the computer simulation.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.1420-1424
• /
• 2011

When it developes the railway system, safety is one of the most important and necessary things. SCADE SUITE has been used in many systems, like plane, transportation, nuclear power, etc, who have high priority to safety. This document introduces where SCADE SUITE has been used and describes how develope safety-critical system with SCADE.

• Nuclear Engineering and Technology
• /
• v.51 no.5
• /
• pp.1289-1296
• /
• 2019

Non-functional requirements plays a critical role in designing variety of applications domain ranges from safety-critical systems to simple gaming applications. Performance is one of the crucial non-functional requirement, especially in control and safety systems, that validates the design. System risk can be quantified as a product of probability of system failure and severity of its impact. In this paper, we devise a technique to do the performance analysis of safety critical and control systems and to estimate performance based risk factor. The technique elaborates Petri nets to estimate performability to ensure system dependability requirements. We illustrate the technique on a case study of Nuclear Power Plant system. The technique has been validated on 17 safety critical and control systems of Nuclear Power Plant.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06b
• /
• pp.135-137
• /
• 2012

Safety Critical 시스템은 예상치 못한 오류가 발생했을 시 인명, 재산 및 심각한 환경 피해 등이 발생 할 수 있는 임베디드 시스템이다. Safety Critical 시스템에는 많은 위험성들이 잠재적으로 존재하기 때문에 치명적인 사고가 발생할 수 있다. 이러한 문제를 방지하기 위해 시스템에 존재하는 위험성을 분석하는 활동이 중요시 되고 있다. 본 연구에서는 Safety Critical 시스템의 잠재적인 위험성들을 분석하고 이를 아키텍처 설계에 반영함으로써 시스템의 안전성을 향상시키기 위한 Hazard Perspective를 제안한다. 제안하는 Hazard Perspective는 위험성 분석으로 산출된 정보들과 SSR(System Safety Requirement)을 시스템의 안전을 보장하기 위해 제시된 여러 Safety Architectural Tactics와 매핑하여 아키텍처 설계에 반영시킴으로써 시스템의 안전성을 향상시키도록 한다.

• Journal of IKEEE
• /
• v.16 no.2
• /
• pp.145-152
• /
• 2012

This paper is the Software Hazard Analysis (SWHA) which will study the managerial process and the technical methode and techniques inherent in the performance of software safety task within the Military Aircraft System Safety program. This SWHA identifies potential hazardous effects on the software intensive systems and provides a comprehensive and qualitative assessment of the software safety. The purpose of this paper is to identify safety critical functions of software in Military A/C. The identified software hazards associated with the design or function will be evaluated for risks and operational constraint to further improve the software design requirement, analysis and testing efforts for safety critical software. This common SWHA, the first time analysis in KOREA, was review all avionics OFP(Operational Flight Program), and focus only on software segments which are safety critical. This paper provides a important understanding between the customer and developer as to how the software safety for the Military A/C will be accomplished. It will also provide the current best solution which may as one consider the necessary step in establishing a credible and cost-effective software safety program.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.571-576
• /
• 2010

In this study, an application method of critical strains concept for tunnels' safety by using the values of measured displacements which are obtained in the field is discussed. The aim is to: (1) study on the engineering meanings of critical strains concept by reviewing the previous researches and application examples with measured displacement values; (2) study on the engineering reasonability of critical strains concept with the view point of a tunnel engineering and a geotechnical engineering; (3) study on the features of ground deformation due to tunneling and reciprocal relation between total displacement and measured displacement; (4) evaluate a tunnel safety by using domestic measurements collected in the field; and (5) re-evaluate the control criteria which were previously used in the field, with the view point of critical strains concept. Consequently, it was confirmed that critical strains in the ground has a reasonability and a possibility of unified or common concept with the view point of a tunnel engineering.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.10
• /
• pp.3885-3892
• /
• 2010

Safety-Critical systems, such as Plant Protection Systems in nuclear power plant, plays a key role that the facilities can be operated without undue risk to the health and safety of public and environment, and those systems shall be designed, fabricated, installed, and tested to quality standards commensurate with the importance of the functions to be performed. Computer-based Instrumentation and Control Systems to perform the safety-critical function have Real Time Operating Systems to control and monitoring the sub-system and executing the application software. The safety-critical Real Time Operating Systems shall be designed, analyzed, tested and evaluated to have capability to maintain a high integrity and quality. However, local nuclear power plants have applied the real time operating systems on safety critical systems through Commercial Grade Item Dedication method, and this is the reason of lack of detailed methodology on assessing the safety of real time operating systems, expecially to the new developed one. This paper presents the methodology and experiences of safety evaluation on safety-critical Real Time Operating Systems based upon design requirements. This paper may useful to develop and evaluate the safety-critical Real Time Operating Systems in other industry to ensure the safety of public and environment.

• Nuclear Engineering and Technology
• /
• v.39 no.2
• /
• pp.129-132
• /
• 2007

It is generally known that software reliability growth models such as the Jelinski-Moranda model and the Goel-Okumoto's non-homogeneous Poisson process (NHPP) model cannot be applied to safety-critical software due to a lack of software failure data. In this paper, by applying two of the most widely known software reliability growth models to sample software failure data, we demonstrate the possibility of using the software reliability growth models to prove the high reliability of safety-critical software. The high sensitivity of a piece of software's reliability to software failure data, as well as a lack of sufficient software failure data, is also identified as a possible limitation when applying the software reliability growth models to safety-critical software.