Approaches to Modeling and Simulation for Dynamic , Distributed Cyber-Physical Systems

In this paper we discuss challenges and new directions in modeling and simulation for effects-based what-if and sensitivity analysis of dynamic, distributed cyber-physical systems. We are motivated on one hand by the critical need to reliably understand how mission-critical cyber-physical systems would respond to unanticipated effects, and on the other hand by the technology gap that has prevented us from doing so until now. Modern cyber-physical systems are very large distributed systems, covering wide geographic areas with time-critical operations, asynchronous state updating and implicit interactions through resource sharing. Canonical examples of such systems include the national electric power generation and distribution grid, computing infrastructure, communication networks and manufacturing systems that are built upon multiple layers of software and physical resources. We address three main aspects of challenges and next steps to the modeling and simulation of these systems based on 1) a revised foundation for model representation, 2) advanced model-analytic tools and 3) a general adaptable and reusable simulation environment. Our suggested approach to these challenges incorporates both the generalization and repurposed use of existing technologies to create a rigorous and justifiable foundation for survivability analysis in largescale cyber-physical systems. Keywords-cyber-physical systems; modeling; simulation; verification; challenges