The current status of the modelling of comminution processes is assessed in light of its capabilities and weaknesses. The principles required for a major upgrade in modelling capability are proposed. The use of advanced computational techniques to provide detailed information on the mechanical environment in comminution devices, linked in with correctly designed breakage tests, underpin this development. These will lead us into more fundamentally correct models that include mineral liberation and can be applied to the design of novel comminution devices. (c) 2006 Elsevier B.V. All rights reserved.