SAFE-Matter™: Evidence Renewal Interval (ERI) Standard — Deterministic Time-Bound Validity for Life-Critical Safety Systems

This paper defines the Evidence Renewal Interval (ERI) as a governing parameter within the SAFE-Matter™ framework, establishing the maximum duration for which verified evidence of a life-critical system’s condition remains valid for reliance.Conventional certification and inspection models verify systems at discrete points in time but do not provide a mechanism for determining whether those systems remain safe at the moment they are relied upon. This creates a structural gap between historical compliance and present-state assurance.The ERI standard addresses this gap by introducing a deterministic, time-bound model for evidential validity. It defines how the reliability of verified system states degrades as time progresses, and establishes explicit thresholds beyond which reliance is no longer justified.The standard introduces a proportional decay model linked to elapsed time relative to assigned ERI values, ensuring consistent and reproducible trust evaluation across equivalent systems. It further defines the UNVERIFIED state as the absence of valid evidence within allowable ERI bounds, preventing reliance on systems whose condition cannot be demonstrated at the moment of reliance.Baseline ERI ranges are defined across SAFE-Matter SM Code families, aligning evidence validity with system function, risk profile, and required responsiveness.This document forms part of the SAFE-Matter evidential safety governance framework, enabling continuous, auditable determination of whether life-critical systems can be trusted in real-world conditions.