The NFI was originally geared to answer questions related to timber production. In the NFI2, however, changes in structure and condition of the forest were registered for the first time. Furthermore, information about the forest's recreational function and the forest as a natural habitat were increasingly evaluated. The effects of avalanches, rockfall and protection forests were also investigated.
The long term goal of the NFI is to obtain detailed knowledge about forest functions and the tree stands' ability to fulfill those functions. The goal and content of the third NFI were clarified with a needs assessment in 2000 and 2001. The data catalog was more or less kept unchanged in the NFI4.