Virtual manufacturing based on through-process modelling becomes an evolving research area which aims at integrating diverse simulation tools to realize computer-aided design,analysis,prototyping and manufacturing.Numerical prediction of the as-cast microstructure is an initial and critical step in the whole throughprocess modelling chain for engineering components.A commercial software package with the capability of calculating important microstructure features for aluminium alloys is used to simulate a G-AlSi7MgCu0.5 laboratory casting.The simulated microstructure,namely grain size,secondary dendrite arm spacing and diverse phase fractions are verified experimentally.Correspondence and discrepancies are reported and discussed.