A polynomial algorithm for checking diagnosability of Petri nets

Diagnosability of discrete event systems was previously defined in terms of finite state machines by Sampath et al. Two algorithms of polynomial complexity in the number of states were proposed later for checking their diagnosability. In this paper, we present an algorithm of polynomial complexity in the number of nodes for computing a sufficient condition of diagnosability of discrete event systems modeled by Petri nets. In other words, our algorithm is more efficient than previous ones since no state enumeration is necessary. This gives us an advantage to solve large real-world problems. Our algorithm is formulated as a linear programming problem, which is well-known to be of polynomial complexity in the worst case. Examples are given in the paper to illustrate our approach.