Integrated RSL Basics

What is an Integrated RSL?

A feature is available on Reliability Strategy Libraries (RSLs) for Health, Safety, Security and Environment (HSSE) Critical Equipment (CE), also called Safety Critical Elements (SCE), that acts as a hardware barrier for major accident hazards.

The Integrated RSL feature identifies the HSSE CE Categories on each assurance task. This identification gives assets a reference point for assurance tasks during the operate phase and defines the functional safety requirements for that equipment.

This identification helps assets to:

• Specify their barriers and assurance criteria.

• Determine appropriate equipment strategies for the safety functions.

• Prevent major accident hazards (MAH) from occurring.

The resulting assurance tasks are meant to ensure that the HSSE CE functions as intended on demand.

Background

Each barrier in the Swiss Cheese Model has its own HSSE CE Category.

The barriers are identified by 8 HSSE CE Categories, from “Structural Integrity” to “Life Saving”.

HSSE Critical Equipment or FLOCs can be marked with the ABC indicator (SAP) or Criticality code (IMS), for example:

Why the Integrated RSL feature exists

Major hazards are identified during a Hazard and Operability study (HAZOP) and developed into Bowtie models. A Bowtie model visualizes how a hazard can escalate, its consequences, and the barriers required to manage it.

Each HSSE CE that results from this analysis has its specification defined to establish integrity, along with the assurance tasks needed to safeguard that integrity during the operate phase.