Proof testing, repair, demand response, bypass management per IEC 61511 Cl.16
Phase 6 covers the operational life of the SIS — proof testing to verify continued SIF integrity, repair upon detected failures, response to actual demand events, and discipline around bypass / override management. Cl.16 also requires a documented Safety Manual that operating teams reference daily.
Phase 6 is where the SIS earns or loses its claimed integrity. Sites with disciplined proof testing maintain SIL claims through 20-year lifecycles; sites without it accumulate undetected failures that surface only during real demand.
Phase 6 generates the operational reliability data that feeds Phase 4 (re-verification when components change) and informs Phase 7 (modification triggers). It also produces the FSA Stage 4 audit evidence that proves SIL claims remain valid.
A focused 6-step methodology calibrated to deliver operation and maintenance as a working capability — not a documented compliance artefact.
Author per SIF — sensor stimulus, logic verification, final-element actuation; specify PTC per coverage analysis.
Execute at calculated interval (T1 from PFD); document as-found / as-left; trigger repair if failures found.
Per Cl.16.4 — MTTR tracking, root cause for revealed failures, FSE notification for systematic patterns.
Per Cl.16.5 — analyse each demand response, verify successful SIF action, identify systematic issues.
Per Cl.16.2 — authorisation hierarchy, time limits, compensating measures, audit log; align with MOC for extended bypass.
Every 3-5 years per OSHA PSM (o) and IEC 61511; review proof-test records, demand responses, modifications.
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.