Probabilistic real-time schedulability: from uniprocessor to multiprocessor when the execution times are uncertain

In this paper we study preemptive fixed- priority scheduling of periodic task systems with execution times that are given by independent random variables. We provide (naive, but efficient) improvements to existing analyses in the case of one processor. These improvements are based on a discussion on the validation of probabilistic schedulability analyses. For the case of several identical processors, we give a new probabilistic schedulability analysis for global fixed-priority scheduling.