Safety Critical Element Management ManualEP 2009-9009
Restricted
18
Figure 7: SCE Identification decision treeDoes 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 CLASSS-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.