The SLS (Selective Laser Sintering) process is now widely used to manufacture polymer parts. However, as with other additive manufacturing (AM) processes for polymers and polymer-based materials, SLS is mainly used for prototyping and not much for industrial scale manufacturing, because the quality and performances obtained with AM are lower than with other more classical processes. The hypothesis of this project is that the quality and performances of SLS products can be improved by better understanding their manufacturing and thus controlling quality through predictive numerical modeling. In this project a physically-based multi-scale numerical modeling will be developed which will predict the influence of the SLS process on the material’s responses starting from the manufacturing stage and up to the final solid part. Important original contributions will concern modeling porosity, crystallinity change and thermo-viscoelastic-viscoplastic coupling. While classical manufacturing processes for polymers (e.g., injection molding) have been studied extensively in the literature, much work remains to be done for AM and especially as related to material modeling.