Functional safety assessment of safety-related systems with non-perfect proof-tests

被引：0
作者：
Muta, Hitoshi [1 ]
Sato, Yoshinobu [2 ]
机构：
[1] Tokyo City University, Tokyo
[2] Japan Audit and Certification Organization for Environment and Quality (JACO), Tokyo
来源：
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences | 2014年 / E97-A卷 / 08期
关键词：
Functional safety; Non-perfect proof-test; Safety integrity level; Safety-related system;
D O I：
10.1587/transfun.E97.A.1739
中图分类号：
学科分类号：
摘要：
The second edition of the international standard of IEC 61508, functional safety of electrical/electronic/programmable electronic safety-related system (SRS), was published in 2010. This international standard adopts a risk-based approach by which safety integrity requirements can be determined. It presents a formula to estimate the hazardous event rate taking account of non-perfect proof-tests. But it is not clear how to derive the formula. In the present paper, firstly, taking account of non-perfect proof-tests, the relationship between the dangerous undetected failure of SRS, the demand on the SRS and hazardous event is modeled by a fault tree and state-transition diagrams. Next, the hazardous event rate is formulated by use of the state-transition diagrams for the determination of the safety integrity requirements. Then, a comparison is made between the formulas obtained by this paper and given in the standard, and it is found that the latter does not always present rational formulation. Copyright © 2014 The Institute of Electronics, Information and Communication Engineers.
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页码：1739 / 1746
页数：7
相关论文
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