Methodology for computer-aided design of granule microstructure is described in this work. Three-dimensional virtual granules with varying porosity and binder-solids ratio have been systematically constructed by random packing of primary particles with simultaneous spreading and solidification of binder droplets. The effective dissolution rates of the granules have then been determined by gradually eroding material from the granule surface according to local fluxes obtained as the solution of a convection-diffusion problem in the surrounding liquid phase. Dissolution maps, i.e. correlations between granule structure, formulation ingredient properties and the dissolution half-time t(50), have been obtained from the simulations.