The progress of silicon technologies we have witnessed in the last twenty years has traced the path to the unprecedented revolution of information technologies, which has changed almost everybody's lifestyles. Apparently, this has happened with a little big help from TCAD tools. Big, because few major advancements have been achieved through the clever exploitation of non-conventional simulation tools, and because everyday device optimization deeply relies on TCAD tools. Little, because the qualitative feeling is that the technology would have progressed anyway, through the work of many highly-skilled technology experts, even without simulation guidelines. The purpose of this paper is to review the state-of-the-art of the field of the transport modeling of electron devices, trying to grasp the essence of the most relevant simulation models proposed so far, whence to contribute to spur the activity on the fundamental modeling of carrier transport.