FSA Stages 1-5 audits per IEC 61511 Cl.5 — independent integrity assurance
Functional Safety Assessment (FSA) is the independent audit cycle that proves the SIS meets its target SIL through design, installation, and operation. Per IEC 61511 Cl.5, FSA is conducted at five lifecycle stages — Stage 1 after H&RA, Stage 2 after design, Stage 3 after installation, Stage 4 every 3-5 years during operation, Stage 5 after modification.
FSA is how the organisation discovers whether the SIS actually achieves what it claims. Sites with rigorous FSA programmes catch systematic failures before they manifest in real demand events; sites without it operate on faith.
FSA validates every lifecycle phase output and feeds findings back to MOC for corrective action. It also provides the third-party evidence that regulators, insurers, and corporate audit require.
A focused 6-step methodology calibrated to deliver functional safety assessment (cross-cutting) as a working capability — not a documented compliance artefact.
Define cadence — Stage 1 / 2 / 3 / 4 / 5; specify auditor competence (TÜV / exida / SIRA certification); document procedures.
Select independent auditor — internal rotation, third-party (TÜV / exida / DNV), or certification body; verify competence.
Per stage — review phase outputs, interview personnel, walk-down installation; document findings per template.
Categorise per severity — critical (immediate correction), major (target date), minor (improvement); align with corrective action database.
Track to closure per target date; verify effectiveness; escalate systematic patterns to FSM.
Issue FSA report per stage; retain records per OSHA PSM (m)(6) and corporate requirements.
Decision-gated workflow showing the actual sequence of activities — from initiation through steady-state operation — with key decision points highlighted.
We can scope this element implementation against your facility, regulatory context, and existing management-system maturity — and integrate it with the other Functional Safety Lifecycle Implementation elements you already operate.