The problems of the statistical analysis of complex functional blocks have been considered. The methods of the statistical analysis and the simulation speedup have been analyzed. The approach, that allows a considerable reduction of the computational costs during the statistical simulation of the complex functional blocks, has been proposed. The proposed approach is based on using the models of the circuit functional parameters, which are calculated as the quadratic forms with the rank 1 matrix. The comparative analysis results are shown for the cases when the linear regression and the least-squares regression are used during the degeneration of the models for the functional parameters of the complex functional blocks.