Failure Mechanisms, Modes, Effects, and Diagnostics Analysis~--- a Novel Approach to Include Predictive Health Monitoring into Functional Safety

This paper proposes a novel approach that integrates modern Reliability Engineering methods, specifically various types of Predictive Health Monitoring (PHM) into the Functional Safety analysis technique of Failure Modes, Effects, and Diagnostics Analysis (FMEDA). This new method is named Failure Mechanisms, Modes, Effects, and Diagnostics Analysis (FMMEDA). FMMEDA can serve as a drop-in replacement for FMEDA, delivering the same hardware-architectural metrics defined in IEC 61508 or ISO 26262. Although it is an open approach compatible with many techniques, this paper focuses on two primary types of PHM. The first type relies on Early Damage Detection. In this case, damage caused by a Failure Mechanism is already detectable before functional Failure manifests through the associated Failure Mode. The second type comprises Physics of Failure based approaches that use sensors to monitor stress parameters and model Remaining Useful Life (RUL). The FMMEDA for both types of PHMs is discussed as well as their principal advantages and limitations. Finally, example implementations of both PHM types are presented and abbreviated FMMEDAs are performed to illustrate the usage of this new analysis method.

Keywords: Safety, Reliability, Predictive analytics, Prognostics and health management, FMEA, FMEDA.