Fault Injection for Software Certification

As software becomes more and more pervasive and complex, it is increasingly important to assure that a system will be safe even in the presence of residual software faults (“bugs”). Software Fault In-jection consists in the deliberate introduction of software faults for assessing the impact of faulty software on the system and improving fault-tolerance. Software Fault Injection has been included as a recom-mended practice in recent safety standards, and it has therefore gained interest among practitioners, but it is still unclear how it can be ef-fectively used for certification purposes. In this paper, we discuss the adoption of Software Fault Injection in the context of safety certifica-tion, present a tool for the injection of realistic software faults, namely SAFE (SoftwAre Fault Emulator), and show the usage of the tool in the evaluation and improvement of robustness of a RTOS adopted in the avionic domain