Generating functionals method of N.N.Bogolyubov and multiple production   physics
  The generating functionals (GF) method in Bogolyubov's formulation and its application for particle physics is considered. Effectiveness of the method is illustrated by two examples. So, GF method can be used as the technical trick solving the infinite sequence of algebraic equations. We will consider the example, where GF allows express the multiplicity distributions (topological cross sections) through the particles correlation functions (inclusive cross sections) to `predict' so called the Koba-Nielsen-Olesen scaling. We will use the GF to define validity of the thermal description of the multiple production phenomena also. It will be seen that this will lead to the `correlations relaxation condition' of N.N.Bogolyubov. This will allow to offer the experimentally measurable criteria of applicability of thermodynamical description of multiple production processes. In results we will find the closed form of perturbation theory applicable for kinetic phase of nonequilibrium processes. It is shown a way as the approach may be adapted to the definite external conditions. 
J.Manjavidze and A.Sissakian