Yokogawa EJX115A - Manual (Page 90)

<Appendix1. Safety Instrumented Systems Installation>
A1-3
IM 01C25T01-06EN
A1.3 Definitions and
Abbreviations
A1.3.1 Definitions
Safety Freedom from unacceptable
risk of harm
Functional Safety The ability of a system to carry
out the actions necessary
to achieve or to maintain a
defined safe state for the
equipment/machinery/plant/
apparatus under control of the
system
Basic Safety The equipment must be
designed and manufactured
such that it protects against
risk of damage to persons
by electrical shock and other
hazards and against resulting
fire and explosion. The
protection must be effective
under all conditions of the
nominal operation and under
single fault condition
Verification The demonstration for each
phase of the life-cycle that the
(output) deliverables of the
phase meet the objectives
and requirements specified by
the inputs to the phase. The
verification is usually executed
by analysis and/or testing
Validation The demonstration that the
safety-related system(s) or
the combination of safety-
related system(s) and external
risk reduction facilities meet,
in all respects, the Safety
Requirements Specification.
The validation is usually
executed by testing
Safety Assessment The investigation to arrive at a
judgment -based on evidence-
of the safety achieved by
safety-related systems
Further definitions of terms used for safety
techniques and measures and the description of
safety related systems are given in IEC 61508-4.
A1.3.2 Abbreviations
FMEDA Failure Mode, Effects and Diagnostic
Analysis
SIF Safety Instrumented Function
SIL Safety Integrity Level
SIS Safety Instrumented System
SLC Safety Lifecycle