Loss ratio of the EDF scheduling policy with early discarding technique

This paper considers a firm real-time M/M/1 system, where jobs have stochastic deadlines till the end of service. A method for approximately specifying the loss ratio of the earliest-deadline-first scheduling policy along with exit control through the early discarding technique is presented. This approximation uses the arrival rate and the mean relative deadline, normalized with respect to the mean service time, for exponential and uniform distributions of relative deadlines. Simulations show that the maximum approximation error is less than 4% and 2% for the two distributions, respectively, for a wide range of arrival rates and mean relative deadlines. (C) 2013 Elsevier B.V. All rights reserved.