In San Antonio, Emerson Exchange 2010 featured a new Meet the Experts concept that provides participants to interact with recognized experts on focused topics. Emerson’s Mike Boudreaux provided a 2 hour session on Safety Lifecycle Management. This was an interactive short seminar that has been designed to help business leaders and managers in the process industries have a general understanding of existing industry standards and best practices for safety instrumented systems. This seminar provides a practical overview of the safety lifecycle, including key considerations for each phase. In addition to the typical design concepts related to safety instrumented functions and safety integrity levels, important concepts such as organizational design, competency management, planning, and continuous verification will be discussed. Part 4 describes the Analysis Phase and explains the managment considerations for hazard and risk assessment, layers of protection analysis, and safety requirements specification.

1. Analysis Phase

4. Allocation of safety functions to protection layers Hazard and risk assessment Source: IEC 61511-3, Figure 4 – Risk and safety integrity concepts

5. Source: IEC 61511-3, Figure 2

6. SIS BPCS Plant and Emergency Response Emergency response layer Containment, Dike/Vessel Passive protection layer Mitigate Fire and Gas System Active protection layer Incident Emergency Shutdown System Safety layer Emergency shutdown Trip level alarm Prevent Process control layer Operator Intervention Operator intervention Process alarm Process control layer Process Value Normal behavior

7. Likelihood Increasing Risk Consequence

8. Likelihood Increasing Risk ALARP Risk Region Unacceptable Risk Region Negligible Risk Region Consequence

9. Likelihood Increasing Risk Inherent Risk of Process ALARP Risk Region Unacceptable Risk Region Negligible Risk Region Consequence

10. Likelihood Increasing Risk Inherent Risk of Process Non-SIS Mitigating Safeguards Baseline Risk Non-SIS Preventative Safeguards ALARP Risk Region Unacceptable Risk Region Negligible Risk Region Consequence

11. Likelihood Increasing Risk Inherent Risk of Process Non-SIS Mitigating Safeguards Baseline Risk SIS Risk Reduction Overall Risk SIL1 Non-SIS Preventative Safeguards ALARP Risk Region Unacceptable Risk Region Negligible Risk Region Consequence

12. Likelihood Increasing Risk Inherent Risk of Process Non-SIS Mitigating Safeguards Baseline Risk SIS Risk Reduction SIL1 Non-SIS Preventative Safeguards SIL2 ALARP Risk Region Unacceptable Risk Region Overall Risk Negligible Risk Region Consequence

13. Likelihood Increasing Risk Inherent Risk of Process Non-SIS Mitigating Safeguards Baseline Risk SIS Risk Reduction SIL1 Non-SIS Preventative Safeguards SIL2 ALARP Risk Region Unacceptable Risk Region SIL3 Overall Risk Negligible Risk Region Consequence

14. Likelihood Increasing Risk Inherent Risk of Process Non-SIS Mitigating Safeguards Baseline Risk SIS Risk Reduction SIL1 Non-SIS Preventative Safeguards SIL2 ALARP Risk Region Unacceptable Risk Region Overall Risk Negligible Risk Region Consequence

15. As low as reasonably practicable (ALARP) Intolerable Risk 10-3 / man-year (worker) 10-4 /year (public) ALARP or Tolerable Risk Region 10-5 / man-year (worker) 10-6 /year (public) Negligible Risk

16. Government mandates for tolerable risk levels 10-2 10-3 10-4 10-5 10-6 10-7 10-8 10-9 Australia (NSW) - Hong Kong - Netherlands - United Kingdom - The United States does not set tolerable risk levels, or offer guidelines.

17. Chemical industry benchmarks for tolerable risk 10-2 10-3 10-4 10-5 10-6 10-7 10-8 10-9 Company I - Company II - Company III - Small companies - Large, multinational chemical companies tend to set levels consistent with international mandates Smaller companies tend to operate in wider ranges and implicitly, at higher levels of risk

20. Quantitative Risk Assessment

21. Qualitative Risk Assessment

22. Qualitative risk analysis – Safety layer matrix

23. Source: Exida Safety and Critical Control Systems in Process and Machine Automation July 2007

24. Safety Requirement Specification

25. Safety Requirement Specification

26. ?