070 – NORWEGIAN OIL AND GAS APPLICATION OF IEC 61508 AND IEC 61511 IN THE NORWEGIAN PETROLEUM INDUSTRY (Recommended SIL requirements) Norwegian Oil and Gas Association Application of IEC 61508 and IEC 61511 in the Norwegian Petroleum Industry (Recommended SIL requirements) 2 of 250 No.: 070 Established: February 2001 Revision no.: 04 Date revised: April 2020 Table of content FOREWORD ................................................................................................................................................................. 4 1 INTRODUCTION ................................................................................................................................................. 5 1.1 SCOPE AND PURPOSE OF GUIDELINE .............................................................................................................. 5 1.2 CONTENT OF GUIDELINE ............................................................................................................................... 5 1.3 CHANGES FROM PREVIOUS VERSION OF THIS GUIDELINE .............................................................................. 6 2 THE IEC 61508 AND IEC 61511 STANDARDS ................................................................................................ 7 3 REFERENCES .................................................................................................................................................... 10 4 DEFINITIONS AND ABBREVIATIONS ......................................................................................................... 12 4.1 DEFINITIONS ............................................................................................................................................... 12 4.2 ABBREVIATIONS ......................................................................................................................................... 13 5 MANAGEMENT OF FUNCTIONAL SAFETY .............................................................................................. 17 5.1 OBJECTIVE .................................................................................................................................................. 17 5.2 RISK REDUCTION, BARRIER MANAGEMENT AND MANAGEMENT OF FUNCTIONAL SAFETY ........................... 17 5.3 COMPETENCE REQUIREMENTS .................................................................................................................... 18 5.3.1 SIS design............................................................................................................................................... 18 5.3.2 SIS follow-up during operation .............................................................................................................. 18 5.4 SAFETY PLANNING ...................................................................................................................................... 19 5.5 FUNCTION SAFETY AUDITS AND REVISIONS................................................................................................. 19 5.6 VERIFICATION ............................................................................................................................................ 19 5.7 VALIDATION ............................................................................................................................................... 20 6 FUNCTIONAL SAFETY ASSESSMENT ........................................................................................................ 21 6.1 OBJECTIVE .................................................................................................................................................. 21 6.2 FSA EXECUTION ......................................................................................................................................... 21 7 DETERMINING SIL REQUIREMENTS ......................................................................................................... 23 7.1 OBJECTIVE .................................................................................................................................................. 23 7.2 APPROACH .................................................................................................................................................. 23 7.3 HAZARD AND RISK ANALYSIS ..................................................................................................................... 25 7.3.1 Scope of hazard and risk analysis .......................................................................................................... 25 7.3.2 Process Hazard Analysis (PHA) ............................................................................................................ 25 7.4 DEFINITION OF SAFETY INSTRUMENTED FUNCTIONS AND SIL ALLOCATION ............................................... 26 7.5 MINIMUM SIL REQUIREMENTS ................................................................................................................... 27 7.6 HANDLING OF DEVIATIONS FROM THE MINIMUM SIL REQUIREMENTS ........................................................ 36 7.6.1 Identification of deviations from the minimum SIL table ....................................................................... 36 7.6.2 Determination of SIL for safety functions where section 7.5 is not applicable ...................................... 36 7.7 SAFETY REQUIREMENTS SPECIFICATION .................................................................................................... 37 8 SIS DESIGN AND ENGINEERING .................................................................................................................. 38 8.1 OBJECTIVES ................................................................................................................................................ 38 8.2 INPUT .......................................................................................................................................................... 38 8.3 SIL REQUIREMENTS ................................................................................................................................... 38 8.3.1 Quantitative requirements ..................................................................................................................... 38 8.3.2 Architectural constraints ....................................................................................................................... 39 8.3.3 Avoidance and control of systematic faults ............................................................................................ 40 8.4 PROVEN IN USE AND PRIOR USE .................................................................................................................. 41 8.4.1 Proven in use ......................................................................................................................................... 41 8.4.2 Prior use ................................................................................................................................................ 41 8.5 REQUIREMENTS TO FAILURE DATA ............................................................................................................ 42 8.5.1 Objective ................................................................................................................................................ 42 8.5.2 SIS data sources ..................................................................................................................................... 42 Norwegian Oil and Gas Association Application of IEC 61508 and IEC 61511 in the Norwegian Petroleum Industry (Recommended SIL requirements) 3 of 250 No.: 070 Established: February 2001 Revision no.: 04 Date revised: April 2020 8.5.3 Achieving the specified risk reduction - requirements to the applied SIS data ...................................... 44 8.6 OTHER ISSUES ............................................................................................................................................. 45 8.6.1 Comparison between sensors ................................................................................................................ 45 8.6.2 HMI – Human Machine Interface .......................................................................................................... 46 8.7 INDEPENDENCE BETWEEN SAFETY SYSTEMS ............................................................................................... 46 8.8 DOCUMENTATION FROM THE DESIGN PHASE ............................................................................................... 47 9 SIS INSTALLATION, COMMISIONING AND VALIDATION .................................................................... 50 9.1 OBJECTIVES ................................................................................................................................................ 50 9.2 REQUIREMENTS .......................................................................................................................................... 50 10 SIS FOLLOW-UP DURING OPERATION.................................................................................................. 51 10.1 OBJECTIVE .................................................................................................................................................. 51 10.2 SIS DOCUMENTATION AND PREMISES FOR OPERATION................................................................................ 51 10.3 SUMMARY OF SIS FOLLOW-UP ACTIVITIES