Creation of mathematical model of complex radical processes manually is a very time-consuming process. Steam-cracking model created automatically by automated reaction network generation, on the other hand, becomes very large and complex for bigger molecules. This work was aimed at applying pseudo-steady state assumption automatically to components inside generated reactions network. The details of simplifying procedure are provided and the comparison of experimental data (lab-scale) to simulations by original and simplified model is presented. In overall, the simplification procedure lead only to marginal deviations in the simulated results, but the model ability to simulate bigger molecules has substantially improved.