Enter your device data. SILVerify performs complete IEC 61508 / 61511 three-barrier SIL verification and generates a professional, FSA-ready report automatically. One session. No spreadsheets. No manual formatting.
The problem isn’t your calculations. The problem is the workflow. Spreadsheets were never designed to produce auditable, client-ready verification documentation. SILVerify was.
My default has always been a spreadsheet. It works, but the gap between a finished calculation and a finished report is where the time goes — and where the risk lives if someone else has to pick it up later. I used SILVerify on a live project and the report it produced was better structured than what I’d have written myself. Everything is traceable from input to conclusion. For anyone doing this work independently, it’s hard to justify the spreadsheet route once you’ve seen the alternative.
SILVerify assesses all three barriers required under IEC 61508 and IEC 61511, and documents data uncertainty per IEC 61511-1 §11.9.4.
Per-channel PFDavg, subsystem totals, relative contribution, three-barrier summary, uncertainty assessment, and achieved SIL — with the limiting subsystem flagged automatically.
| Subsystem | Architecture | PFDavg (channel) | Subsystem PFDavg | Contribution |
|---|---|---|---|---|
| Sensors (PT-001A/B) | 1oo2 | 3.68 × 10-4 | 1.77 × 10-4 | |
| Logic Solver (LS-001) | 1oo1 | 6.17 × 10-4 | 6.17 × 10-4 | |
| Final Elements (XV-001) | 1oo1 | 4.38 × 10-3 | 4.38 × 10-3 | |
| Total SIF PFDavg | — | — | 5.17 × 10-3 | SIL 2 ✓ |
⚠ Final elements contribute 85% of total PFDavg — limiting subsystem. Design changes should target final element architecture before any other subsystem.
| SIL 2 acceptance range | 1.00 × 10-3 — 1.00 × 10-2 |
| Lower bound (÷3) | 1.72 × 10-3 |
| Best estimate PFDavg | 5.17 × 10-3 |
| Upper bound (×3) | 1.55 × 10-2 ⚠ exceeds SIL 2 range |
| Verdict | PASS — marginal (warning only). Recommend targeting PFDavg ≤ 3.33 × 10-3 for full margin. |
HFT is derived automatically from the declared architecture. The 2oo2 case — where HFT = 0 regardless of channel count — is assessed correctly and the architectural constraint consequence is stated explicitly in the report.
Baseline single-channel architecture. One failure causes safety function loss. Standard for logic solvers and single-channel final elements where the reliability target is met without redundancy.
Two channels, either activates the function. One failure tolerated — HFT = 1. Improves both PFDavg and the architectural constraint position. Common cause failure (beta factor) required.
Both channels must function. HFT = 0 — identical to 1oo1. Reduces spurious trip rate but does not improve the safety architectural position. Selecting 2oo2 to improve a SIL claim via Route 1H is a common and costly design error.
Three channels, 2-of-3 voting. One failure tolerated — HFT = 1. Higher PFDavg than 1oo2 for identical channel failure rates. Beta factor required.
The report reads from a frozen input snapshot — it never re-queries live data. The document always represents the exact calculation run it was generated from. All previous reports are stored permanently and never overwritten.
SILVerify accelerates the work of a qualified functional safety engineer. It does not replace engineering judgement. Scope boundaries are explicit in every report it generates.
Delivering SIL verification on client projects across multiple sites and standards. SILVerify turns 2–4 days of calculation and writeup into a single session. The report goes to the client — complete, documented, signed by you.
Managing a SIS on an operating facility. SILVerify provides a documented history of every calculation — essential when a modification is proposed, when regulatory inspection is imminent, or when a previous calculation needs to be defended.
Multiple engineers across multiple projects requiring consistent methodology and report format. Team licensing provides a shared tool and shared output format — ending the problem of reconciling three different engineers’ spreadsheet approaches on the same project.
“I built SILVerify because I was sick of the workflow. The calculation was the easy part. Then came checking it again. Then the Word document. Then reformatting every table because a SIF changed. On a project with ten SIFs that process consumed days. SILVerify exists because that time belongs on the engineering, not the paperwork. The defensibility is the point — but getting your time back is a very close second.”
Your device library keeps building value. Your project history is preserved. Your next modification takes minutes, not days.