What is a Safety Critical Element (SCE)?
SCE’s consist of any element (hardware, software and systems) which
- Prevents the occurrence/realization of a Major Accident Hazard; or
- Where in it’s absence a Major Accident Hazard can be realised
Some examples of SCE’s in the Process Industry:
- Pressure Relief Systems
- Blowdown Systems
- Critical Alarms
- Safety Shutdown Systems
- Emergency Power
What is SCE Management?
SCE Management is a process of:
- Identification of Major Accident Hazards and associated SCE’s;
- Developing Performance Standards for each SCE containing
- Functionality of the element;
- Availability of the element;
- Reliability of the element;
- Survivability of the element; and
- Interdependency of the element with others.
- Developing Asset Integrity and Assurance Plans;
- Execution / Verification of Integrity Assurance Exercise throughout facility lifecycle; and
- Applying Change Management Process when necessary.
The following Guideline is available from the UK HSE
SCE Management is Important Because:
- Enables Identification and accurate understanding of the functions of critical safety critical equipments / systems in a Major Hazard Facility;
- Enables Focused Maintenance of critical safety critical equipments / systems in a Major Hazard Facility;
- Enables Systematic and cost effective assurance / maintenance exercise on the SCEs;
- Prevents / Minimizes on-demand failure of SCEs; and
- Ensures that SCE’s are given priority for Maintenance in a facility.
The Means of SCE Identification:
- Develop the SCE List Using Guidance from standards such as API RP 14C; or
- Use quantitative / semiquantitative techniques like HAZID/HAZOP/LOPA and BowTies
ARMADA EHS 