Independence and non-interference: two cardinal concepts to develop EE architectures hosting safety-critical systems

摘要

A presentation of the typology of dependent failures (Common Cause Failures, Common Mode Failures and Cascading Failures) will be used to explain the distinction between the concepts of independence and absence of interference introduced in the ISO26262 future automotive safety standard. Independence of EE architectural elements is required particularly between two architectural elements implementing a function and its associated safety mechanism. Absence of interference which is less demanding than independence is required to allow architectural elements of different criticality to cohabit (among others, safety-related elements and non-safety-related elements). Typical EE automotive examples will support this discussion.