With the ever increasing amount of precise data available for lepton-hadron processes, the perturbative QCD framework can be extended to explore effects and corrections that go beyond the next-to-leading order (NLO) accuracy. We have investigated some of those corrections such as threshold resumption of soft gluon emission for hadron multiplicities and spin asymmetries, Hadron Mass Corrections (HMC) and their interplay for Deep-Inelastic Scattering (DIS) and Semi-Inclusive e+ e- Annihilation, and next-to-next-to leading order (NNLO) corrections to the longitudinal structure function for Semi-Inclusive DIS (SIDIS). We also present our study towards a global NNLO fit of Fragmentation Functions together with the extension to the small x-region which we are currently working on.