Real-time systems sometimes need to be formally proven, especially realtime systems containing critical component, as planes, cars etc. Timed automata provide a convenient mathematical model for this. However, although they provide a representation of the temporal aspects of these systems, timed automata assume arbitrary precision and zero-delays actions. Therefore, even if a state is declared reachable in a timed automaton, it is sometimes impossible to reach it in the physical system it models. The aim of this thesis is to model a type of perturbation, on delays, for timed automata and to compute the most permissive strategies to solve this imprecision problem. These strategies propose intervals of delays instead of the usually proposed single delays. These strategies seek to reach one of the final states of the automaton regardless of the delay, in the proposed interval, that has occurred.