We present an extended method of automatic behavioral model generation for nonlinear analog circuits. The focus is on a decrease of simulation time. A procedural model formulation approach is introduced, together with a new simplification method based on the recognition of physical transistor properties of the element models. The simplification process is performed with respect to simulation time, and a hierarchical modeling approach is proposed. The result of these extensions are models with an obvious speed-up in simulation time compared to the simulation of the original netlists.