Since the Tunnel-FET is handled to be the successor of the current MOSFET technology, reliability in terms of the fabrication process becomes more and more an issue. In our previous work [1] high current variances could be observed for random dopant fluctuations (RDF) in Tunnel-FET devices. In this paper a comparative numerical analysis of RDF in MOSFETs and Tunnel-FETs is done in order to show the different influences of this effect in these devices. In the simulation randomized profiles are implemented by using the Sano method [2]. An analytical model is presented to estimate the gate voltage variation due to RDF in MOSFETs.