Execution Admissibility at the Moment of Reliance: A Formal Statement of Evidentiary Requirement for Life-Critical Systems

Modern safety and control systems operate on the basis of detection, validation, and execution. Within this structure, conditions are established and evidenced during detection and validation phases, but are not re-established at the point of execution. As a result, systems proceed on the basis of prior validation rather than contemporaneous evidence of condition. This paper defines a formal requirement for execution admissibility at the moment of reliance. It establishes that reliance upon a life-critical system is only justified where the operational condition of that system is evidenced at the point of execution through evidence that is contemporaneous, attributable, and verifiable. Where such evidence is absent, incomplete, or cannot be verified, the condition of the system must be treated as unproven. In such cases, reliance is not justified and the system is not admissible for the purpose for which it is being relied upon. This requirement reframes safety from a model based on historical compliance to one based on present-state evidential condition. It introduces a binary admissibility boundary at the moment of reliance and establishes absence of evidence as a defined and actionable state. The requirement applies across mechanical, electrical, digital, and cyber-physical systems, and across all safety-critical domains including detection, suppression, containment, communication, control, and evacuation.