When Is CAN the Weakest Link? A Bound on Failures-in-Time in CAN-Based Real-Time Systems

A method to bound the Failures In Time (FIT) rate of a CAN-based real-time system, i.e., the expected number of failures in one billion operating hours, is proposed. The method leverages an analysis, derived in the paper, of the probability of a correct and timely message transmission despite host and network failures due to electromagnetic interference (EMI). For a given workload, the derived FIT rate can be used to find an optimal replication factor, which is demonstrated with a case study based on a message set taken from a simple mobile robot.