System Safety Assessment (SSA)

[ARP4761:] The SSA process flow is generally represented through succeeding levels of verification.  Through these upward hierarchical verification levels, hardware reliability requirements, architectural requirements and hardware and software Development Assurance Levels are verified against the safety requirements delineated in the PSSA process.

The system safety assessment presents the body of proof that the qualitative and quantitative safety requirements established by the FHA and PSSA are satisfied by the as-built item or system.   Substantiation is provided by the results of quantitative FMEA / FMES, FTA, cutset analyses, qualitative common cause analyses (CCA) and nonanalytic activities (e.g., special tests, demonstrations and inspections) deemed prudent and necessary to complete a comprehensive assessment.