Software FMEA techniques

Assessing the safety characteristics of software driven safety critical systems is problematic. The author has performed software FMEA on embedded automotive platforms for brakes, throttle, and steering with promising results. Use of software FMEA at a system and a detailed level has allowed visibility of software and hardware architectural approaches which assure safety of operation while minimizing the cost of safety critical embedded processor designs. Software FMEA has been referred to in the technical literature for more than fifteen years. Additionally, software FMEA has been recommended for evaluating critical systems in some standards, notably draft IEC 61508. Software FMEA is also provided for in the current drafts of SAE ARP 5580. However, techniques for applying software FMEA to systems during their design have been largely missing from the literature. Software FMEA has been applied to the assessment of safety critical real-time control systems embedded in military and automotive products. The paper is a follow on to and provides significant expansion to the software FMEA techniques originally described by the author in the 1993 RAMS paper "Validating The Safety Of Real-Time Control Systems Using FMEA".