Modeling infrastructure interdependencies using Petri nets

The infrastructure of many nations has become a very complex inter-connection of electric power distribution systems, oil and natural gas production facilities, transportation (pipelines) of these products, water supplies, and communications. In addition, each of these systems is intertwined and heavily dependent on each other. The challenge is to model these interdependencies, identify vulnerabilities, and determine specific recovery strategies. This paper demonstrates the use of Petri nets for addressing this challenge. Petri nets are a graph-based tool and this work has shown that the Petri net incidence matrix captures the relationships between the infrastructure components. The place invariants (P-invariants) have been shown to model the interdependencies and identify vulnerabilities. The transition invariants (T-invariants) determine specific recovery strategies. In addition, the graphical nature of Petri nets allows a simple visualization of the interdependencies by observation of the token flows through the net.