The objective of the present work is to study the raster generation to realize Fused Filament Fabrication parts. The research in this paper focused on the evaluation of the deposition of a simple geometry with a FFF machine, supported by an analytical model to compute the build time, also evaluating the geometrical variations caused by changes in process parameters. The main parameters were the print temperature and speed as a function of the thermal and rheological properties of the PLA filament. The study identified essential correlations between process parameters, raster dimensions, and filament properties. An experimental procedure, supported by an analytical model, was implemented for computing raster time and material dimensions.