Dynamic scheduling in the presence of faults : specification and verification

A distributed real-time program is usually executed on a limited set of hardware resources and is required to satisfy timing constraints, despite anticipated hardware failures. Static analysis of the timing properties of such programs is often infeasible. This paper shows how to formally reason about these programs when scheduling decisions are made on-line and take into account deadlines, load and hardware failures. We use Timed CCS as a process language, define a language to describe anticipated faults and apply a version of a mu-calculus to specify and verify timing properties. This allows the property of schedulability to be the outcome of an equation-solving problem. And unlike conventional reasoning, the logic is fault-monotonic: if correctness is proved for a number of faults, correctness for any subset of these faults is guaranteed