An approach to capture system interaction failures of a complex system

This paper addresses two main issues pertaining to currently available failure analysis (FA) techniques that are applicable in early product design stages: (i) their inability in capturing many unanticipated system interactions that lead to many failure modes being left unaccounted for, after FA has been conducted; and (ii) their inability in identifying root causes of failure modes that have already been captured. To address these issues, this paper proposes a cognitive map based FA framework that facilitates the generation of a wide variety of failure modes including system interaction failures in early design stages by effectively capturing the propagation of causality. It also presents a convenient basis for performing root cause analysis of identified failures using a mathematically rigorous backtracking algorithm. The proposed framework lends the much required quantitative formalism to design stage FA in generating failure modes as well as in tracking down the root causes of failures identified. A typical electric water heater is taken as example to demonstrate the applicability of the framework.