First Out

Using First Out AI

First Out AI guide: from HAZOP row to LOPA to SIF target

How the HAZOP, LOPA, SIL verification and SRS tabs connect, step by step.

2 min read · First Out AI knowledge library

  1. HAZOP worksheet: record the deviation with one specific cause, the consequence without safeguards and the safeguards by tag. Rank S and L.
  2. LOPA → Add scenario (or import your LOPA sheet): copy the cause and consequence, enter IEF with its source, the TMEL with its basis, enabling conditions, conditional modifiers and IPLs with their PFDs and independence evidence. Link the SIF.
  3. Calculate (or Calculate all for every scenario). The frequency chart shows the gap the SIF must close.
  4. Apply to linked SIF: the target SIL and required PFDavg go to the function in SIL verification.
  5. SIL verification → Calculate against the required PFDavg, not just the SIL band.
  6. SRS and proof test: the SRS quotes the LOPA scenario, its layers and result, and HAZOP rows that mention the SIF tag.
  7. Cause & effect → Build from SIFs to start the matrix.

Ask First Out AI in the LOPA tab "Which of my protection layers may not be independent?" for a review of the scenario you have open.

Written for First Out AI as engineering guidance. It supports engineering work and does not replace it; check every value against your standards, certificates and company rules with a competent functional safety engineer.