Cyber-Physical Systems Based Modeling of Dependability of Complex Network Systems

We use the cyber-physical systems (CPS) framework to infuse intelligent adaptation behaviors in complex network systems to achieve dependability. The CPS framework is anchored on "intelligent physical worlds" (IPW) around which complex adaptation behaviors are built. An IPW is an embodiment of control software functions wrapped around the raw physical processes (e.g., servers, links, sensors, actuators), performing the core system activities while adapting its behavior to the changing environment conditions and user inputs. The IPW exhibits an intelligent behavior over a limited operating region of the system (in contrast with traditional models where the physical world is dumb). To perform over wide operating regions, the IPW interacts with an intelligent computational world (ICW) to patch itself with control parameters and procedures relevant in those changed conditions. The modular decomposition of an application into IPW and ICW lowers the design complexity of dependable network systems, and simplifies the system verification/testing.