Fuzzy Fault Trees: the Fast and the Formal

Abstract

We provide a rigorous framework for handling uncertainty in quantitative fault tree analysis based on fuzzy theory. We show that any algorithm for fault tree unreliability analysis can be adapted to this framework in a fully general and computationally efficient manner. This result crucially leverages both the alpha-cut representation of fuzzy numbers and the coherence property of fault trees. We evaluate our algorithms on an established benchmark of synthetic fault trees, demonstrating their practical effectiveness.

Preprint version, containing an appendix with proofs, of the conference paper with the DOI below; presented at QEST+FORMATS 2025. (This replacement corrects the faulty DOI from the previous version and updates this comment field.)