EN
The aim of the present research was to determine the models of the work consumption characteristics at the work-stand of the operator of the NIAB 5-15 processor aggregated with the farm tractor. Modelling consisted in approximating the mathematical functions which described the processes under analysis. The present research was conducted in pine, fir and spruce stands during early and late thinnings, where timber skidding, debranching and manipulation was performed. The research results indicate the occurrence of proportional relations between work consumption and the volume of the harvested timber, certain elements of the working day timing and the index of the quantitative intensity of harvesting which characterizes the percentage of the number of trees removed from a stand.