Automatic Generation of Static Fault Trees from AADL Models

Abstract

Safety-critical systems, such as avionics systems and medical devices, are developed with stringent safety requirements. System safety analysis provides assurance that the system in consideration satisfies these safety constraints. Traditionally, safety analysis is performed manually based on various informal requirements and design documents. Recent work in the area of model-based safety analysis,where safety analysis is based on a central formal model of the system, has helped demonstrate some key advantages of this methodology, including automatic generation of safety artifacts. Although most of this work is still far from being mature, we believe that this methodology holds promise in making the safety analysis process more formal, automated, consistent, and most importantly in helping tightly integrate the safety and systems engineering processes. We also believe that it is crucial to have a flexible modeling notation to capture both the system and the failure information to be able to derive “realistic� safety analysis. To corroborate our position, in this paper, we describe our prototype tool for automatically generating static fault trees based on architectural AADL models that can be input into a commercial fault tree analysis tool, CAFTA. We also put forth some challenges that we encountered that are potentially applicable to other approaches to automating generation of safety artifacts.