B.3.4:8 - Rationale

An earlier result can remain valid for its earlier claim while no longer supporting a changed use. Conversely, elapsed time need not defeat an unchanged premise. Maintenance therefore follows the assurance argument and its conditions rather than a universal entropy metaphor.

B.3’s source account and ISO/IEC/IEEE 15026-2:2022 place maintenance with assurance cases. C.27.TA supplies the use-relative temporal qualification. This pattern adapts those distinctions to continued reliance and planning; it attributes no universal decay equation or mandatory expiry date to the standard. A validated domain deterioration model or an applicable review rule can justify a particular time-based policy and its reconsideration conditions.