Decentralized failure diagnosis of stochastic discrete event systems

In decentralized diagnosis the system behavior is monitored at multiple local sites, each possessing its own sensors and making its own local diagnosis decision without communicating with other sites. In this paper we formalize the decentralized diagnosis for stochastic DESs by introducing S-Codiagnosability, supplementing the notion of SS-Codiagnosability first introduced by Liu, et al. We also give polynomial algorithms for checking (i) necessity and sufficiency of SS-Codiagnosability, (ii) sufficiency of S-Codiagnosability, and (iii) necessity as well as sufficiency of S-Codiagnosability, which requires an additional notion of equivalence of probabilistic automata.