| Presentation | 2004/8/17 Difference between hazardous event rates obtained by two stochastic models Itaru YOSHIMURA, Yoshinobu SATO, Koichi SUYAMA, |
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| PDF Download Page | PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | Recently computer systems are widely applied to various fields for implementation of safety functions. This general trend forced IEC to compile IEC 61508 as a standard related to functional safety of electrical/electronic/programmable electronic safety-related system, I.e. E/E/PE SRS (hereinafter SRS). Lately Japanese Industrial Standard included the translated standard JIS C 0508. The standard requires assessing the risk reduction achieved by SRS using appropriate probabilistic techniques for allocation of safety integrity levels (SILs) to SRS. However, the relationships among SILs, operation modes and hazardous event rate have not been always cleared up yet. Then, two formulas are presented using a Markovian model and sequential failure logics in order to describe causation of hazardous events in the overall system and to estimate hazardous event rate in the dynamic demand state of SRS. The present paper compares those two models and verifies their applicability to generic overall systems. Namely, the difference between two formulas is much less than the values which is able to change the SILs for SRS on actual time between proof tests and longer ones. Thus, it is concluded that both of the precise estimation by the Markovian model and approximate estimation by the sequential failure logics are useful for the estimation of hazardous event rates of generic overall systems. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | Functional Safety / Safety Integrity Level / Hazardous Event Rate / Markovian Model / Sequential Failure Logic |
| Paper # | SSS2004-17 |
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| Conference Information | |
| Committee | SSS |
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| Conference Date | 2004/8/17(1days) |
| Place (in Japanese) | (See Japanese page) |
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| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Safety (SSS) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Difference between hazardous event rates obtained by two stochastic models |
| Sub Title (in English) | |
| Keyword(1) | Functional Safety |
| Keyword(2) | Safety Integrity Level |
| Keyword(3) | Hazardous Event Rate |
| Keyword(4) | Markovian Model |
| Keyword(5) | Sequential Failure Logic |
| 1st Author's Name | Itaru YOSHIMURA |
| 1st Author's Affiliation | Tokyo University of Marine Science and Technology() |
| 2nd Author's Name | Yoshinobu SATO |
| 2nd Author's Affiliation | Tokyo University of Marine Science and Technology |
| 3rd Author's Name | Koichi SUYAMA |
| 3rd Author's Affiliation | Tokyo University of Marine Science and Technology |
| Date | 2004/8/17 |
| Paper # | SSS2004-17 |
| Volume (vol) | vol.104 |
| Number (no) | 256 |
| Page | pp.pp.- |
| #Pages | 5 |
| Date of Issue | |