The complexity of friction phenomena results from their being inherently multiscale. The computer aided design of tribocontacts is therefore able to handle all scales of the atomistic description of the contact up to the elasto-hydrodynamics of the lubrication gap. Quantum chemical calculations describe possible reactions between basic lubricants, additives, oxygen and the involved surface. Molecular dynamic simulations provide the boundary conditions for continuum-mechanical lubricant simulations. Molecular dynamic and mesodynamic simulations shed light on the impact of micro - and nanostructuring of tribo surfaces on friction behavior and prescribe design rules for structuring. Mesoscopic modelling of the dynamics of non-Newtonian lubricants contributes to the optimization of shear flows.