Massimo is a distance and position independent single tree growth model based on the grid of the Swiss National Forest Inventory. The modules for growth, mortality, disturbance and management are based on empirical models that were fit from NFI- data. Massimo is used to predict future timber harvesting potentials, to assess climate protection effects of the Swiss forest and timber industries, and to define the forest management reverence level FMRL under the Kyoto-protocol.