IEC 61508-6:2010 Annex D maps common-cause score bands to β factors of 0.5%–5% for logic subsystems and 1%–10% for sensors and final elements
0.5–5% logic; 1–10% sensors/final elementsobserved
| Value kind | observed — Reported measurements, counts, and specifications keep the precision and scope stated by their source; an exact specification is not treated as a range. |
|---|---|
| Scope | Hardware common-cause bands in the IEC functional-safety context; no portable data-center β. Score the subsystem with the Annex D checklist before using a band. |
| As of | 2010-04-30 |
| Source | IEC 61508-6:2010 Annex D (Table D.4 score bands); exida guidance on the β ranges · IEC 61508-6:2010 Annex D, Table D.4: score bands for logic subsystems (0.5/1/2/5%) and sensors/final elements (1/2/5/10%); exida blog paragraph citing Annex D |
| Review | checking…review by 2027-03-08 · slow cadence |
| Recorded changes | last 2026-09-16 · 3 revisions tracked |
| Claim id | iec-61508-beta-factor-range-for-common-cause |
Where the guide uses it
← Full numbers register — every date-stamped figure in the guide, with revision history.