ANALYSIS TYPE / 10
Common Cause · Common Mode · Independent Channel Verification
Overview
Dependent Failure Analysis (DFA) identifies common cause failures (CCF) and common mode failures (CMF) that could simultaneously affect independent or redundant channels — a mandatory activity for ASIL C and ASIL D systems under ISO 26262. Our DFA process combines structured checklists, independence verification reviews, and quantitative CCF factor analysis to confirm that the redundant architecture achieves the required level of independence and that residual CCF risk is within acceptable bounds.
Industries Served
Standards
Key Aspects
Identifying shared resources — power supplies, ground planes, temperature environments, software platforms — that could cause concurrent failure in supposedly independent channels.
Evaluating design similarities between redundant channels that could produce identical failure responses to the same input stimulus — defeating diversity.
Verifying that spatial, thermal, electrical, and software separation between redundant channels is sufficient to prevent correlation of failures.
Specifying design changes — diversity, isolation, physical separation, or monitoring — to reduce CCF and CMF contributions to an acceptable level.
Connect with our functional safety team to define the right approach, timeline, and tooling for your project.
