Automatic Architecture Hardening Using Safety Patterns

Safety critical systems or applications must satisfy safety requirements ensuring that catastrophic consequences of combined component failures are avoided or kept below a satisfying probability threshold. Therefore, designers must define a hardened architecture or implementation of each application, which fulfills the required level of safety by integrating redundancy and safety mechanisms. We propose a methodology which, given the nominal functional architecture, uses constraint solving to select automatically a subset of system components to update and appropriate safety patterns to apply to meet safety requirements. The proposed ideas are illustrated on an avionics flight controller case study.