The role of atomic-scale computations in the Integrated Computational Materials Science methodology applied to Al castings at Ford will be described. First-Principles atomic-scale computational methods are becoming increasingly used in industry due to their predictive power. However, their computational complexity often limits their use to relatively simple systems. Hence, we have focused on coupling first-principles methods with other computational approaches such as phase-field microstructural evolution models, computational thermodynamics or CALPHAD methods, and cluster expansion methods and kinetic Monte Carlo. The resulting combined models have been applied to alloys in the Al-Si-Cu-Mg system, and applications to precipitation, heat treatment, mi-crostructural evolution, and yield strength have proved fruitful.