This paper investigates potential to improve fault-detection coverage by means of on-chip redundancy. The international standard on functional safety, namely, IEC61508 Ed. 2.0 Part 2 Annex E.3 prescribes the upper bound of βIC (common cause failure (CCF) ratio to all failures) is 0.25 to satisfy frequency upper bound of dangerous failure in the safety function for SIL (Safety Integrated Level) 3. On the other hand, this paper argues that the βIC does not necessarily have to be less than 0.25 for SIL 3, and that the upper bound of βIC can be determined depending on failure rate λ and CCF detection coverage. In other words, the frequency upper bound of dangerous failure for SIL3 can also be satisfied with βIC higher than 0.25 if the failure rate λ is lower than 400[fit]. Moreover, the paper shows that on-chip redundancy has potential to satisfy SIL 4 requirement; the frequency upper bound of dangerous failure for SIL4 can be satisfied with feasible ranges of βIC, λ and CCF coverage which can be realized by redundant code.
Nobuyasu KANEKAWA
Hitachi, Ltd.
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Nobuyasu KANEKAWA, "Potential of Fault-Detection Coverage by means of On-Chip Redundancy - IEC61508: Are There Royal Roads to SIL 4?" in IEICE TRANSACTIONS on Information,
vol. E96-D, no. 9, pp. 1907-1913, September 2013, doi: 10.1587/transinf.E96.D.1907.
Abstract: This paper investigates potential to improve fault-detection coverage by means of on-chip redundancy. The international standard on functional safety, namely, IEC61508 Ed. 2.0 Part 2 Annex E.3 prescribes the upper bound of βIC (common cause failure (CCF) ratio to all failures) is 0.25 to satisfy frequency upper bound of dangerous failure in the safety function for SIL (Safety Integrated Level) 3. On the other hand, this paper argues that the βIC does not necessarily have to be less than 0.25 for SIL 3, and that the upper bound of βIC can be determined depending on failure rate λ and CCF detection coverage. In other words, the frequency upper bound of dangerous failure for SIL3 can also be satisfied with βIC higher than 0.25 if the failure rate λ is lower than 400[fit]. Moreover, the paper shows that on-chip redundancy has potential to satisfy SIL 4 requirement; the frequency upper bound of dangerous failure for SIL4 can be satisfied with feasible ranges of βIC, λ and CCF coverage which can be realized by redundant code.
URL: https://global.ieice.org/en_transactions/information/10.1587/transinf.E96.D.1907/_p
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@ARTICLE{e96-d_9_1907,
author={Nobuyasu KANEKAWA, },
journal={IEICE TRANSACTIONS on Information},
title={Potential of Fault-Detection Coverage by means of On-Chip Redundancy - IEC61508: Are There Royal Roads to SIL 4?},
year={2013},
volume={E96-D},
number={9},
pages={1907-1913},
abstract={This paper investigates potential to improve fault-detection coverage by means of on-chip redundancy. The international standard on functional safety, namely, IEC61508 Ed. 2.0 Part 2 Annex E.3 prescribes the upper bound of βIC (common cause failure (CCF) ratio to all failures) is 0.25 to satisfy frequency upper bound of dangerous failure in the safety function for SIL (Safety Integrated Level) 3. On the other hand, this paper argues that the βIC does not necessarily have to be less than 0.25 for SIL 3, and that the upper bound of βIC can be determined depending on failure rate λ and CCF detection coverage. In other words, the frequency upper bound of dangerous failure for SIL3 can also be satisfied with βIC higher than 0.25 if the failure rate λ is lower than 400[fit]. Moreover, the paper shows that on-chip redundancy has potential to satisfy SIL 4 requirement; the frequency upper bound of dangerous failure for SIL4 can be satisfied with feasible ranges of βIC, λ and CCF coverage which can be realized by redundant code.},
keywords={},
doi={10.1587/transinf.E96.D.1907},
ISSN={1745-1361},
month={September},}
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TY - JOUR
TI - Potential of Fault-Detection Coverage by means of On-Chip Redundancy - IEC61508: Are There Royal Roads to SIL 4?
T2 - IEICE TRANSACTIONS on Information
SP - 1907
EP - 1913
AU - Nobuyasu KANEKAWA
PY - 2013
DO - 10.1587/transinf.E96.D.1907
JO - IEICE TRANSACTIONS on Information
SN - 1745-1361
VL - E96-D
IS - 9
JA - IEICE TRANSACTIONS on Information
Y1 - September 2013
AB - This paper investigates potential to improve fault-detection coverage by means of on-chip redundancy. The international standard on functional safety, namely, IEC61508 Ed. 2.0 Part 2 Annex E.3 prescribes the upper bound of βIC (common cause failure (CCF) ratio to all failures) is 0.25 to satisfy frequency upper bound of dangerous failure in the safety function for SIL (Safety Integrated Level) 3. On the other hand, this paper argues that the βIC does not necessarily have to be less than 0.25 for SIL 3, and that the upper bound of βIC can be determined depending on failure rate λ and CCF detection coverage. In other words, the frequency upper bound of dangerous failure for SIL3 can also be satisfied with βIC higher than 0.25 if the failure rate λ is lower than 400[fit]. Moreover, the paper shows that on-chip redundancy has potential to satisfy SIL 4 requirement; the frequency upper bound of dangerous failure for SIL4 can be satisfied with feasible ranges of βIC, λ and CCF coverage which can be realized by redundant code.
ER -