Solidification simulations are commonly used in the foundry industry in order to predict defects in castings and optimize the production process. Indeed, numerical simulation is an integral part in the design and the development of those products. The solidification of castings is a combination of macro-scale and micro-scale phenomena. The fluctuations of the local composition of the liquid metal during the phase change influences the solidification behavior of the alloy and the impacts shrinkage formation. Various models exist but are often restricted to applications in steel casting or simulation results are not confirmed with experimental data on castings. The aim of this project is to develop a multi-component segregation and shrinkage porosity formation model for solidification, applicable to Al-alloys. First, experimental data are generated with different types of solidification on several aluminum alloys. Those data allow the development of a numerical model that involves heat flow, mass and species flow, fluid flow and solidification dynamics. The impact will be to take into account the effect of the segregation of alloying elements on the solidification behavior of castings and, therefore, allow accurate prediction of the location of shrinkage porosity defects.