What you need before you start
| Item | Where it usually comes from | Field in First Out AI |
|---|---|---|
| Hazard and target (SIL, required PFDavg) | LOPA or risk graph | Target SIL, Required PFDavg (or LOPA tab → Apply) |
| Devices in the loop and their voting | P&ID, C&E, loop diagrams | Subsystem groups, Voting |
| Failure rates λDU, λDD, λSU, λSD | Certificates, FMEDA reports, field data | Rates per group, Source of the rates |
| Element type and systematic capability | Certificate, safety manual | Element type, SC |
| Common cause β | Company checklist | β, βD |
| Proof test interval and coverage | Maintenance plan, test procedure | T1, PTC |
| Partial stroke | Valve diagnostics plan | PST interval, coverage |
| Repair times | Maintenance organisation | MTTR, MRT |
| Mission time, renewal | Plant life, overhaul plan | Mission time, Renewal |
| Safe state, timing, setpoints, reset, bypass | Process design, operations | Specification details |
Order of work
- SIL verification → Add function (or load an example close to your case and edit it).
- Enter the groups in series: sensors, logic solver, final elements. One group per voted set of identical devices.
- Enter failure rates with their source; set T1, PTC, β.
- Calculate. Read the verdict, the group shares and the engineer's reading.
- If the target is not met, use the what-if and ask First Out AI which change is cheapest.
- Fill the specification details; open SRS and proof test for the drafts; download them as Word.
- Save the project (server on paid plans, or Download file).
Import instead of typing
Download the SIF template from SIL verification → Download template, fill one row per group in Excel, and import it. Rows with the same tag form one function.
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.