Contribution of Electromagnetic Interference to the Safety of Complex Systems: Reasoning on Safety Processes and Assurance

Electromagnetic Interference (EMI) can contribute to the emergence of safety hazards in the operation of complex systems throughout various industries. This has led to the specification of Electromagnetic Compatibility (EMC) standards which aim to minimise the impact of EMI on the performance of the systems. Complying with these standards has historically been the only argument for achieving safety in the system. However, due to the rising complexity of the electromagnetic environment and the increasing complexity and autonomy of systems, the need for a risk-based approach has been more felt. A risk-based approach toward EMI, highlights the necessity of a methodology to not only mitigate the impact of EMI on safety but to produce safety assurance arguments as complying with EMC standards may not be adequate to provide safety assurance for a system while employing a risk-based EMI management.
In this thesis, the EMI-related safety arguments produced by the rule-based approach and the state-of-the-art risk-based approach are investigated and the deficiencies of the current safety argument in regard to the contribution of EMI toward safety are identified. The features of an adequate methodology are also identified. Then, an EMI-aware safety assurance methodology is proposed. The methodology is proposed to be followed during the development of the system and to produce essential safety arguments and supporting evidence. Moreover, as part of the methodology, the concept of Electromagnetic Operational Domain Model (EODM) is defined which facilitates the specification of operational conditions in which the system is assured against the contribution of EMI to the safety of the system. Evaluation of the methodology is carried out by peer reviews, case study and analysis. It demonstrated that the methodology can be integrated into system development processes and provides adequate arguments and supporting evidence in regard to the contribution of EMI to the system's safety.