In the foundry processes the hard modeling based on physical-mathematical formula is burdened with simplifications resulting from both: knowledge level on description of particular phenomena and level of theirs complexity. Trends observed in modeling of foundry processes and expectations of users compared with creators’ up-grades propositions are discussed. The author presents real possibilities of efficient modeling validation considering that limits of multiphysics/multiscale modeling exist for massive cast-iron castings, including the zones infected by degenerated structure (e.g. chunky graphite, dross inclusions). The model validation demands experimental-simulation studies. In the paper also the stress grid castings made of lamellar cast-iron are presented as an example of experimental model validation including the thermomechanical properties of cast-iron and furan mould and applying special Hot Distortion (HDplus®) tests of this sand. The validation of thermo-mechanical model was carried out with the use of Comsol system and chosen foundry simulation code.