Integration of the Functional Hazard Assessment within a Model-based System Engineering Framework

Abstract

The aviation industry is turning to novel aircraft concepts and systems to meet challenging environmental targets. New concepts such as hybrid and distributed electric propulsion add increasing complexity to aircraft system architectures. The systems architecting process must thus be modified to identify promising architectures early in the design process. Safety assessment plays a major role in the certification of aircraft systems and thus must be adapted to evaluate novel architectures in early design stages. At the same time, model-based systems engineering (MBSE) is used increasingly for system specification. The safety assessment process is following a similar trend, the so-called Model-Based Safety Assessment (MBSA), which is promising for complex systems architectures. This paper presents how a model-based specification can be used to conduct a Functional Hazard Analysis (FHA), a first step to integrating MBSE with the safety assessment process. A practical framework using the Capella tool is presented. An aircraft brake system example illustrates the effectiveness of the presented methodology using a variety of models and diagrams. Overall, the presented paper improves current MBSE and safety assessment practices for more effective development of future aircraft.