Length of restoration sequences for systems without information loss

The paper deals with the problem of controlling the behaviour of discrete type systems in case when hardware back-up is absent or faulty, and direct modification of their behaviour in the process of functioning, i. e. controlling the behaviour of these systems on the basis of their functional redundancy, is impossible or not expedient. A finite determinate automaton is used as a mathematical model of the system. The lengths of restoration sequences for the class of group automata are estimated.