Safety Critical Element Management Manual EP 2009-9009 Restricted 18 Figure 7: SCE Identification decision tree Does the system or equipment belong to any of the SCE groups shown in the HSE case bow tie? Q1. Has the system or equipment been subject to a credible RRM assessment Q3. Is the system or equipment inline with the hazard scenarios in the HSE case hazard register for Major Hazards? Q2. Non-SCE ? ? ? No Yes No No No Yes Yes SCE identification SCE SCE ü ü SCE ü SCE ü SCE ü S-RCM CRITICALITY CLASS S-RBI CRITICALITY CLASS SIFPro SIL Level Criticality is High (H) or Extreme (E) Criticality is High (H) or Extreme (E) Criticality Negligible (N), Low (L, Medium (M) or Medium High (MH) Criticality Negligible (N), Low (L, Medium (M) or MediumHigh (MH) Non-SCE Non-SCE Non-SCE Non-SCE SIL=>1 SIL=a1 or a2 Yes i.e. risk is ABC, DE, DE or 3E In RAM assessment, is the system or equipment criticality at severity 5 or red risk? Q4.
