Network Systems Analysis in Case of Critical Situations

The paper describes the analysis and discussion of the network systems in case of the critical situation that happens during ordinary work. The formal model is proposed - based on the two types of real sophisticated network systems - with the approach to its modelling based on the system behaviour observation. The definition of the critical situation sets are created by reliability, functional and human reasons. No restriction on the system structure and on a kind of distribution describing the system functional and reliability parameters is the main advantage of the approach. The proposed solution seems to be essential for the owner and administrator of the transportation systems.