Safety Integrity Levels for GOVERNANCE

Safety Integrity Levels (SILs) are four discrete levels of safety performance of safety-related systems that use electrical and/or electronic and/or programmable electronic (E/E/PE) technologies as defined in IEC 61508.

To minimise dangerous failures of such systems, R2A typically uses the following process to determine the required safety allocation of E/E/PE SIL. The process involves the following tasks:

• Establish all credible, critical threat/hazard scenarios.

• Develop threat barrier sequences.

• Determine barrier SILs.

• Allocate and determine E/E/PE SILs (if required).

• Analyse E/E/PE SIL hazard control system failures.

• Review sign-off.

R2A’s engineers deliver a governance & SFAIRP process to satisfy safety case arguments for E/E/PE SIL allocation since, inter alia, it should be comprehensible to judges and juries as well as senior management, that is, satisfy the requirements of the WHS legislation across Australia — OHS Act in Victoria — and the common law, thereby demonstrating due diligence.