YOKOGAWA AXW4A - Definitions and Abbreviations

IM 01E21A21-02EN
<2. Safety Instrumented Systems Installation>
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2.3 Denitions and Abbreviations
2.3.1 Denitions
● Safety
Denition Contents
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
dened 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 re and
explosion. The protection must be e󰀨ective under all conditions of the nominal operation
and under single fault condition.
● Verication
Denition Contents
Verication The demonstration for each phase of the life-cycle that the (output) deliverables of the
phase meet the objectives and requirements specied by the inputs to the phase. The
verication 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 Specication. 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 denitions of terms used for safety techniques and measures and the description of safety-related
systems are given in IEC 61508-4.
2.3.2 Abbreviations
Denition Contents
FMEDA Failure Mode, E󰀨ects and Diagnostic Analysis
SIF Safety Instrumented Function
SIL Safety Integrity Level
SIS Safety Instrumented System
SLC Safety Lifecycle