Summary. Modern technical systems used in practice (machines, vehicles, military technology) are subject to automatic degradation of the technical condition, which forces modelling to identify changes in this state. The available modelling methods in identifying changes in the technical condition of such systems make it possible to supervise the developing threats to the correctness of their functioning. This paper presents the available methods and tools for modelling and identifying evolving threats to complex technical systems, in terms of description and indications of the premises for their use. Modern technical systems (machines and military technology) are characterized by such features as functionality, reliability, readiness, security, mobility, and operational vulnerability. Identification of threats to the functioning of technical systems through modelling therefore concerns the construction of models of the test object, the reconstruction of the state of the object and its prediction. The existing methods of identification can be divided into methods of identifying static and dynamic properties. The current availability of computers and simulation studies of the dynamics of objects allows attempts to identify the dynamic properties of objects throughout its life cycle, using various models. Knowledge of the dynamic state and structure of the system makes it possible to describe its behaviour and to build prognostic models of the system's behaviour as a function of dynamic evolution time, based on the growth model of technical condition symptoms.