Greek Letters

β: Beta factor for common cause failures (for DU failures)

β_D: Beta factor for common cause failures (for DD failures)

λ_DD : Rate of Dangerous Detected failures (failures per hour)

λ_DU : Rate of Dangerous Undetected failures (failures per hour)

λ_SD : Rate of Safe Detected failures (failures per hour)

λ_SU : Rate of Safe Undetected failures (failures per hour)

From A to L

BPCS: Basic Process Control System  (also DCS)

CC: Common Cause

CCF: Common Cause Failure

Cpt: Coverage of Proof Tests  (also PTC)

DC: Diagnostic Coverage [λ_DD / (λ_DU + λ_DD)]

DCS: Distributed Control System  (also BPCS)

DTT: De-energized To Trip

E/E/PE: Electrical, Electronics, and Programmable Electronic

ESD: Emergency Shut Down

ETT: Energized To Trip

EUC: Equipment Under Control

FAT: Factory Acceptance Tests

FC: Fail Close (valve close when power/air failure)

FE: Final Element  (actuator subsystem)

F&G: Fire & Gas

FIT: Failures in Time (failures per billion hours; λ=FIT x 1E-9)

FMEA: Failure Mode and Effect Analysis

FMEDA: Failure Modes, Effects, and Diagnostic Analysis

FO: Fail Open (valve open when power/air failure)

FST/FVST: Full Valve Stroke Test

GUI: Graphic User Interface

HAZID: Hazard Identification study

HAZOP: Hazard and Operability study

HFT: Hardware Fault Tolerance

HIPPS: High Integrity Pressure Protection System

HMI: Human Machine Interface

HP: High Pressure

ICSS: Integrated Control & Safety System

IEC: International Electrotechnical Commission

IPL: Independent Protection Layer

IS: Intrinsically Safe

LT: Life Time of the SIF  (also MT)