The general approach to fault tolerance in uniprocessor systems is to use time redundancy in the schedule so that any task instance can be re-executed in presence of faults during the execution. In this paper a scheme is presented to add enough and efficient time redundancy to the RateMonotonic (RM) scheduling policy for periodic real-time tasks. This scheme can be used to tolerate transient faults during the execution of tasks. For performance evaluation of this idea a tool is developed.