Model-based Safety Analysis of a Flap Control System

Fault tree analysis is a widely adopted technique to systematically analyze causes for a given failure of a complex system. Traditionally, a fault tree is constructed top-down based on knowledge about the structure of the system and the interaction of subsystems. With the increasing system complexity and the accompanying introduction of model-based development techniques in the industrial process, a substantial amount of this knowledge is laid down in the system models. The main focus of the presented techniques and tools is to automatically exploit this knowledge by extracting a fault tree suitable for FaulTree+ directly from a given design modeled in Statemate. The resulting fault tree is complete wrt. the specified failure, i.e. the analysis considers every possible causal failure combination which is guaranteed by applying model checking techniques. Using an aircraft Flap control system this paper shows how to smoothly integrate the technique into an existing model-based process.