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Math Terms
Terms that are used for various mathematical functions within functional safety. These terms are often part of PFDavg and STR, the two most pressing calculated values.
- Beta Factor
- Diagnostic Coverage (DC)
- Diagnostic Coverage Dangerous (DCdang)
- Diagnostic Coverage Safe (DCsafe)
- Diagnostic Test Interval (DTI)
- Dispersion Analysis
- Failure Rate (λ)
- Lifetime
- Mean Detection Time (MDT)
- Mean Repair Time (MRT)
- Mean Time Between Failure (MTBF)
- Mean Time to Fail Spurious (MTTFsp)
- Mean Time to Failure (MTTF)
- Mean Time to Restore (MTTR)
- Probability of Failure on Demand (PFD)
- Probability of Failure per Hour (PFH)
- Probable Loss of Life (PLL)
- Proof Test Coverage (Cpt)
- Proof Test Interval (TI)
- Risk Reduction Factor (RRF)
- Safe Failure Fraction (SFF)
- Spurious Trip Rate (STR)
Glossary Category
Glossary Catalog
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- Factory Acceptance Test (FAT)
- Failure Modes and Effects Analysis (FMEA)
- Failure Modes, Effects, and Diagnostic Analysis (FMEDA)
- Failure Rate (λ)
- Fault Tree Analysis (FTA)
- Final Element
- Five Nines of Reliability (99.999% Uptime)
- Fixed Programming Language (FPL)
- Full Variability Language (FVL)
- Functional Narrative
- Functional Safety Assessment (FSA)
- Functional Safety Management (FSM)
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- Machinery Safety
- Main Interlock List (MIL)
- Major Accident
- Markov Model
- Maximum Permitted Repair Time (MPRT)
- Mean Detection Time (MDT)
- Mean Repair Time (MRT)
- Mean Time Between Failure (MTBF)
- Mean Time to Fail Spurious (MTTFsp)
- Mean Time to Failure (MTTF)
- Mean Time to Restore (MTTR)
- Mechanical Integrity Program (MI)
- Mode of Operation
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- PEAR Model - People, Environment, Asset, Reputation
- Physical Failure
- Prior Use
- Probability of Failure on Demand (PFD)
- Probability of Failure per Hour (PFH)
- Probable Loss of Life (PLL)
- Process Hazard Analysis (PHA)
- Process Safety Information (PSI)
- Process Safety Management (PSM)
- Process Safety Time (PST)
- Product Safety Manual
- Programmable Electronic System (PES)
- Proof Test
- Proof Test Coverage (Cpt)
- Proof Test Interval (TI)
- Proven In Use
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- Safe Failure Fraction (SFF)
- Safety Instrumented Function (SIF)
- Safety Instrumented System (SIS)
- Safety Integrity Level (SIL)
- Safety PLC
- Safety Requirements Specification (SRS)
- Safety Torque Off (STO)
- Semi-Quantitative Risk Analysis
- SIL Certificate
- SIL Declaration of Conformity
- SIS Safety Lifecycle
- Site Acceptance Test (SAT)
- Site Integration Test (SIT)
- Smart Logic Module
- Spurious Trip Rate (STR)
- Stated Risk
- Stated Risk Tolerance
- Systematic Capability
- Systematic Failure
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