Many real-time systems have rm real-time requirements which allow occasional deadline violations but discard any jobs that are not nished by their deadlines. To measure the performance of such a system, a quality of service (QoS) metric is needed. Examples of often used QoS metrics for rm real-time systems are average deadline miss rates and (m; k)- rm constraint. However, for certain applications, these metrics may not be adequate measures of system performance. This thesis introduces a novel QoS constraint for networked feedback control systems. We show that this constraint can be directly related to the control system's performance. We then present three di erent scheduling approaches with respect to this QoS constraint. Experimental results are provided to compare our scheduling algorithms with EDF and another scheduling algorithm for rm real-time system.