FS中我们会遇见的术语及含义

王天泽

CCF, Common Cause Failure（共因失效）
A situation where several subsystems fail due to a single event. All failures are caused by the event itself and are not consequences of each other.
DC, Diagnostic Coverage（诊断覆盖率）
Describes the effectiveness of fault monitoring of a system or subsystem. It is the ratio (0～100%) between the failure rate of detected dangerous failures and the failure rate of total dangerous failures.
E/E/PES（电气/电子/可编程电子系统）
Electric/Electronic/Programmable Electronic Systems
FMEA, Failure mode and effect analysis（失效模式和后果分析）
Is a systematic technique for failure analysis. A FMEA is often the first step of a system reliability study. It involves reviewing as many components, assemblies, and subsystems as possible to identify failure modes, and their causes and effects. For each component, the failure modes and their resulting effects on the rest of the system are recorded in a specific FMEA worksheet. A FMEA is used to structure mitigation for risk reduction based on either failure (mode) effect severity reduction or based on lowering the probability of failure or both.
FS, Functional Safety（功能安全）
Functional Safety is part of the overall safety that depends on a system or equipment operating correctly in response to its inputs.
Safety function（安全功能）
A function designed for adding safety to a machine whose failure can result in an immediate increase in risk(s).
MTTFd, Mean Time To dangerous Failure（平均危险失效时间）
Expectation of the average time for a dangerous failure to occur.
PFHd, Probability of dangerous Failure per Hour（每小时危险故障概率）
Average probability of dangerous failure taking place during one (1) hour. PFHd is the value that is used for determining the SIL or PL value of a safety function.
PL, Performance Level（性能等级）
Levels (a, b, c, d, e) for specifying the capability of a safety system to perform a safety function under foreseeable conditions.
Safety（安全）
This is freedom from unacceptable risk of physical injury or of damage to the health of people, either directly or indirectly as a result of damage to property or to the environment.
SIL, Safety Integrity Level（安全完整性等级）
Levels (1, 2, 3, 4) for specifying the capability of an electrical safety system to perform a safety function under foreseeable conditions. Only levels 1-3 are used in machinery.
SILCL, SIL Claim Limit（安全完整性要求限制）
Maximum Safety Integrity Level (SIL) that can be claimed for an electrical safety system, taking account of architectural constraints and systematic safety integrity.
Subsystem（子系统）
A component of a safety function that has its own safety level (SIL/PL) that affects the safety level of the whole safety function. If any of the subsystems fail, the whole safety function fails.