FUNCTIONAL SAFETY - SAFETY INSTRUMENTED SYSTEMS FOR THE PROCESS INDUSTRY SECTOR - PART 3: GUIDANCE FOR THE DETERMINATION OF THE REQUIRED SAFETY INTEGRITY LEVELS
International Electrotechnical Committee
FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms, definitions and abbreviations
Annex A (informative) - Risk and safety integrity - general
guidance
Annex B (informative) - Semi-quantitative method - event
tree analysis
Annex C (informative) - The safety layer matrix method
Annex D (informative) - A semi-qualitative method: calibrated
risk graph
Annex E (informative) - A qualitative method: risk graph
Annex F (informative) - Layer of protection analysis (LOPA)
Annex G (informative) - Layer of protection analysis using a
risk matrix
Annex H (informative) - A qualitative approach for risk
estimation & safety integrity level (SIL) assignment
Annex I (informative) - Designing & calibrating a risk graph
Annex J (informative) - Multiple safety systems
Annex K (informative) - As low as reasonably practicable
(ALARP) and tolerable risk concepts
Bibliography
This part of IEC 61511 provides information on: – the underlying concepts of risk and the relationship of risk to safety integrity (see Clause A.4); – the determination of tolerable risk (see Annex K); – a number of different methods that enable the safety integrity level (SIL) for the safety instrumented functions (SIF) to be determined (see Annexes B through K); – the impact of multiple safety systems on calculations determining the ability to achieve the desired risk reduction (see Annex J).
| Document Type | Standard |
| Status | Current |
| Publisher | International Electrotechnical Committee |
| Committee | TC 65 |
| Supersedes |
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