1 Sensitivity Analysis for Real-Time Systems

The correctness of a real-time system depends on not only the running results but also on the time at which results are produced. A hard real-time system is required to complete the operations before all the timing deadlines. For a given task set, what is the maximum allowed execution time of a specific task? What is the minimum speed of the processor? What is the minimum relative deadline or the minimum period of a specific task? These are the questions from engineering real-time systems. In this paper, we answer all these questions by a simple iteration, we proved that the optimal (the minimum or the maximum) task parameter for a EDF-scheduled system can be determined by a single pass of the QPA algorithm which provides efficient and exact schedulability test for real-time systems, and there is no extra search or cost required by the parameter computation. Hence the approaches for the sensitivity analysis are as efficient as QPA, and they are easily incorporated into a system design support tool