A General Framework for Quantitative Modeling of Dependability in Cyber-Physical Systems: A Proposal for Doctoral Research

The overarching objective of the proposed doctoral researches to build a qualitative and quantitative understanding of dependability in cyber physical systems (CPS).The existing body of knowledge includes frameworks and techniques for assessment, modeling, and simulation of the physical and cyber infrastructures, respectively, but such isolated analysis is incapable of fully capturing the interdependencies between these infrastructures. Understanding these interdependencies is a critical precursor to accurate representation and modeling of the CPS as a whole, especially with respect to dependability.The physical water distribution infrastructure, coupled with the hardware and software that support intelligent water allocation, comprise the model CPS that will be used as a case study for the proposed research. A preliminary literature review has been carried out on dependability modeling for CPS, with very sparse results. Allocation algorithms for water distribution have also been investigated,with game theory appearing to hold the most promise.An agent-based approach is suggested for linking the cyber and physical layers, where the agents retrieve information from sensors monitoring the physical components and provide this information to the cyber components. Fault injection will be used to investigate the propagation of failures between the cyber and physical layers. Markovian models will be used to capture the manifestation of cyber and/or physical faults as failures in water allocation, or containment of contaminants.