Sensitivity analysis of real-time task sets

Though schedulability analysis has matured to the point where it is now possible to analyse realistic systems, there is still a lack of flexibility as far as the designer is concerned. Feasibility tests often provide little or no indication of the changes in task timing characteristics required to achieve a feasible system, nor any indication of the extent to which the worst case execution times of tasks may be increased without causing deadlines to be missed (in the case of a feasible system). In practice, however, it is useful to know how sensitive system feasibility is to changes in task timing characteristics. We give a general approach to the sensitivity analysis of task sets, which aids system developers in incorporating changes to the system whilst ensuring that the schedulability guarantees remain intact.