The numerical tools that are integrated in the M5 model of stirred media milling include the Discrete Element Method (DEM) for macroscale simulations, Finite Element Method (FEM) based Fluid-Structure Interaction (FSI) for mesoscale simulations and combined FEM and DEM for microscale simulation of grinding bead impacts. Statistical analyses of the impacts derived by DEM at a macro-level are used for optimization of the mill design and its operational parameters. The thermo-mechanical and hydrodynamical phenomena that occur at the mesoscopic FSI scale between the approaching grinding beads are analyzed by FEM for various impact scenarios with different combinations of impact velocity, direction and rotation as a function of macroscopic mill design. Therefore, the M5 concept takes into account global-local coupling so that the influences of macroscopic design can be derived at nano levels by downscale coupling of influential phenomena.