Two formal methodologies of Model-Based Safety Assessment for Fault Tree Analysis

During the design of safety-critical systems, the automatic estimation of the reliability of a proposed architecture could be a valuable asset. In the aerospace sector, according to ARP4754A [17] and ARP4761 [16] standards, the design development process must be performed in parallel with the safety assessment process. The practical reason is that an archi-tecture that does not comply with safety requirements must be modified accordingly as soon as possible. This article illustrates two existing techniques for automatically generating fault tree evaluations from an architectural model. A discussion of their advantages and possible industrial implementation is provided, together with a practical case study.