Hierarchical Modeling Fault-Error-Failure Dependencies for Cyber-Physical Systems

While cyber-physical system (CPS) has grown in size and complexity, the existing single node failure of system are confronting some serious challenges. The strong coupling of software and physical processes in the emerging field motivates the development of new methods to respond to failure in both the cyber and physical domains. This paper presents formalized definitions for CPS from the view of hierarchical level model. The relationships between faults, errors and failures in the resource, service and process level are introduced. The application of stochastic Petri nets (SPN) on fault-error-failure dependencies Model in CPS is presented. Based on the model analyzing, the Fault-Error-Failure dependency relationships between resource, service and process are presented. The simulation results show the chances of resource faults are larger than the service error; the effects of a non-detected error perceived from resource level are less than that for the service level.