Glossary; Terms From Din En Iso 13849; Terms From Din En 61508 - HYDAC ELECTRONIC HLT 1000 Mode D'emploi

10 Glossary

10.1 Terms from DIN EN ISO 13849

Abbreviation Meaning
MTTF Mean Time To Dangerous Failure
D
DC Average Diagnostic Coverage
avg
CCF Common Cause Failure
PL Performance level

10.2 Terms from DIN EN 61508

Abbreviation Meaning
SIL Safety Integrity Level
HFT Hardware Failure Tolerance
SFF Safe Failure Fraction
MooN M out of N architecture
PFH Probability of a Dangerous Failure per Hour
FMEDA Failure Mode, Effects and Diagosis Analysis
λ Rate for safe detected failures
sd
λ Rate for safe undetected failures
su
λ Rate for dangerous detected failures
dd
λ Rate for dangerous undetected failures
du
DC Diagnostic coverage of safe failures
s
DC Diagnostic coverage of dangerous failures
d
FIT Failure In Time (1 FIT = 1 failure / 10
MTBF Mean Time Between Failure
MTTF Mean Time To Failure
MTTR Mean Time To Repair
9
hours)
9