Probabilistic scheduling guarantee analysis for jobs in stochastic soft real-time systems

Stochastic soft real-time systems distinguish themselves from hard real-time systems in that there is no demand for every job in a task to meet its deadline. For these systems, provided that job deadline missing rate is below some threshold, total performance is acceptable. For a fixed-priority pre-emptive scheduled soft real-time system, we present a probabilistic time demand analysis (PTDA) technique by which a lower bound on the probability that a job in a periodic task meets its deadline is estimated. We have also performed a simulation study of an example system and check the tightness of the lower bound. The simulation results show PTDA has a high speed and an error below 10%.