Following the completion of the second Swiss National Forestry Inventory (Landesforstinventar – LFI) and in the run up to the third Swiss National Forestry Inventory, the effects of the two inventories, which were carried out in the periods 1983-1985 and 1993-1995, were analysed (Impact Analysis LFI1 and LFI2) and the need for a third survey ascertained (Demand Analysis LFI3). The formal bases (programme agreements), LFI services (outputs) and LFI utilisation (impacts) were evaluated and recommendations formulated for the future implementation of the LFI. Based on structured interviews with individual experts and extensive discussions with expert groups, the questions to be answered in the third LFI were formulated. These expected responses are grouped in accordance with the Helsinki criteria and priorities defined for the Swiss state, cantons and research. Eight modules were created for the design of the third LFI, thus creating an important decision-making basis on which to judge its implementation capacity and for the financing.