STPA and SFHA Combined: Airbus A320 Family ATA 27B High-Lift System Case Study

This paper explores the integration of System-Theoretic Process Analysis (STPA) and System Functional Hazard Analysis (SFHA) as a combined approach for safety assessment, using the Airbus A320 family ATA 27B High-Lift system as a case study. The proposed approach utilizes the complementarity of STPA and SFHA: STPA focuses on interactions and control flaws among system or components, identifies scenarios that traditional methods may not consider, while SFHA provides a structured assessment of functional hazards and their severity. By beginning with STPA analysis to identify potential loss scenarios, the following SFHA can be performed in a more comprehensive manner, extending its scope beyond hardware failures to include software issues and human related factors. Output of merging STPA and SFHA shows improvement in hazard identification and assessments.