Robustness of a Class of Non-ordinary Petri Nets

Robustness analysis provides an alternative way to analyze a perturbed system to quickly respond to resource failures. Nonordinary Petri nets have weighted arcs and have the advantage to compactly model operations requiring multiple parts or resources. In this paper, we consider a class of non-ordinary flexible assembly/disassembly Petri net (NFADPN) models and study its robustness properties. Due to the routing flexibility in NFADPN, there may exist different ways to accomplish the tasks. To take advantage of the alternative routes without enforcing liveness for the whole system, we generalize the concept of persistent production proposed to NFADPN. We propose a condition for persistent production. We extend robustness analysis to NFADPN by exploiting its structure. We identify several patterns of resource failures and characterize the conditions to maintain operation in the presence of resource failures. Keywords—Petri net, robustness, failure