Disciplined Failure-Mode Decomposition for Reliability Data Analysis: When the Risks Framework Applies, When it Misleads, and the Practical Questions That Tell the Difference
The decision to model failure mechanisms as competing risks or to treat them as independent processes requiring separate analyses is among the most consequential a reliability engineer makes. The choice cannot be settled by software, by professional habit, or by the convenience of an aggregated dataset. It can be settled only by a clear understanding of the physics of failure, the timing of risks exposure, and the empirical evidence that two or more mechanisms genuinely overlap on the timeline of an asset’s service life. This white paper sets out the discipline that distinguishes legitimate failure mode competing-risks modelling from analytically convenient over-aggregation, the framework that follows from each choice, and the practical questions a practitioner should pose before adopting either approach.