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Doc No. 0418D10SD01 – Rev.01 www.LiutaioCES.com
%WC Percentage Weight Contribution on the Total PFDavg value
1oo1 One(1) out of One(1) safety channel architecture.
1oo2 One(1) out of Two(2) safety channel architecture.
1oo2D One(1) out of Two(2) safety channel architecture with included additional Diagnostics among channels to verify safety channels interoperability.
1oo3 One(1) out of Three(3) safety channel architecture.
2oo2 Two(2) out of Two(2) safety channel architecture.
2oo3 Two(2) out of Three(3) safety architecture.
2oo3D Two(2) out of Three(3) safety channel architecture with included additional Diagnostics among channels to verify safety channels interoperability.
3oo3 Three(3) out of Three(3) safety channel architecture.
Beta (β) Common Cause Failure factor for Dangerous UnDetected failures
BetaD (βD) Common Cause Failure factor for Dangerous detected failures
BPCS Basic Process Control System
CCF Common Cause Failure
CMF Common Mode Failure
CPU Central Processing Unit
CRV Cartridge Valve
DC (or CDD) Diagnostic Coverage factor for Dangerous failures
DCS Distributed Control System. See "PCS".
E/E/PE Electrical, Electronic, Programmable Electronic safety-related system
ESV Emergency Shutdown Valve
Et Proof Test Effectiveness
EUC Equipment Under Control
FE Final safety Element
FIT Failure In Time (1x10-9 per hour).
FMEA Failure Modes and Effects Analysis
FMEDA Failure Modes, Effects and Diagnostic Analysis
FSE Final Safety Element
FSM Functional Safety Management
FSP Functional Safety Plan
FVST Full Valve Stroke Test
GUI Graphic User Interface
HART Highway Addressable Remote Transducer protocol
HAZID Hazard Identification Study
HAZOP Hazard and Operability Study
HFT Hardware Fault Tolerance
HIPPS High Integrity Pression Protection System
HMI Human Machine Interface
HPA Hazard Process Analysis
IPF Instrumented Protective Function
IPS Instrumented Protective System
IS Intrinsically Safe
K, or Kfactor Efficiency of inter-channel comparison / automatic switch mechanism in the 1oo2D Safety Architecture. Fraction of the success of the autotest circuit in the 1oo2D system
LdDD, or lDD Dangerous detected failure rate
LdDU, or lDU Dangerous UnDetected failure rate
LdSD, or lSD Safe detected failure rate
LdSU, or lSU Safe UnDetected failure rate
MART Maximum Allowed Response Time (see “SRT”)
MRT Mean Restoration Time
MSLS Main Safety Loop Series
MSSTRDL Maximum “Spurious Trip Rate” (STR) Safety Design Limit
MTBF Mean Time Between Failures
MTTF Mean Time To Failure
MTTFD Mean Time To Dangerous Failure
MTTFs Mean Time To Failure Spuriously
MTTFspuriously Mean Time To Failure Spuriously
MTTR Mean Time to Restoration
N/A Not Applicable
NA Not Applicable
NDE Normally De-Energized
NE Normally Energized
NIS Non-Intrinsically Safe
OOS Out Of Service
PCS Process Control System. See "DCS".
PE Programmable Electronic
PHA Process Hazard Analysis
PRV Pressure Relief Valve
PST Process Safety Time
PTC Proof Test Coverage
PVST Partial Valve Stroke Test
QSV Quick Shutdown Valve
RBD Reliability Block Diagram
RO Restriction Orifice
RPN Risk Priority Number
RRF Risk Reduction Factor
SCA Safety Channel Architecture
SFF Safe Failure Fraction
SIF Safety Instrumented Function
SIL Safety Integrity Level
SIS Safety Instrumented System
SLf Service Life
SmPosT Smart Position Transmitter
SOV Solenoid Valve
SPST Single Pole Single Trough
SRS Safety Requirements Specification
SRT Safety Response Time
STL Spurious Trip Level
STR Spurious Trip Rate
STRavg Average Spurious Trip Rate
TBDbC To be defined by calculation case
TD Proof test Duration
TI Proof Test Period
XooN X-out-of-N voting logic, or “Safety Channel Architecture” (SCA) of N inputs/Channels where “X” inputs/Channels decide the whole SCA state.
XooN(D) Same SCA as "XooN", but additional diagnostic are included to verify safety channels interoperability.