Analyzing Stochastic Fixed-Priority Real-Time Systems

Traditionally, real-time systems require that the deadlines of all jobs be met. For many applications, however, this is an overly stringent requirement. An occasional missed deadline may cause decreased performance but is nevertheless acceptable. We present an analysis technique by which a lower bound on the percentage of deadlines that a periodic task meets is determined and compare the lower bound with simulation results for an example system. We have implemented the technique in the PERTS real-time system prototyping environment [6, 7].