Decentralized Diagnosis of Discrete-Event Systems Using Labeled Petri Nets

In this paper, we propose an approach to the diagnosis of Petri nets in a decentralized setting that combines the decentralized scheme for automata presented by Debouk et al. with the diagnosis approach for Petri nets based on the notion of basis markings and justifications presented by some of the authors of this paper. The decentralized architecture that we use is composed of a set of sites communicating their diagnosis information with a coordinator that is responsible for detecting the occurrence of failures in the system. In particular, we define three protocols that differ in the amount of information exchanged between the local sites and the coordinator and the rules adopted by the coordinator to compute the global diagnosis states. Finally, we prove that, as in the case of automata, diagnosability is strictly related to the presence of failure ambiguous strings.