At present, many domestic and international researches of network system survivability mainly focused on theoretical research, and the status of complex network system are studied by use of the classical mathematical theory. In fact, the network system status has the uncertainty, randomness and so on. In this paper, taking the survivability of trusted network as the background, the key issues of network survivability are researched. Taking into account the uncertainty, randomness of network system, by introducing cloud model and deterministic finite automaton, the network system status are descript and detected in this paper. Based on cloud model, this paper proposed the network system status’ assessment and forecast model, and the associated theory analysis and confirmation are given. Finally, the feasibility and reasonableness of this model is further confirmed by the aid of simulation experiments. At the same time, this model proposed in this paper enlightened also a new way for study on the survivability of current complex network system.
