Simulation-based techniques are the defacto standard for the verification of industrial designs. Since verification effort takes about 70% of the time of the design phase, it is important to expedite the simulation process in order to reduce the overall verification effort. Modeling-based techniques play an important role towards achieving the speed-up by expediting many subtasks of the overall verification process. In this paper we present a study of the different modeling techniques that are primarily used for semi-formal verification of modern-day industrial digital and mixed-signal designs and the efficacy of the same for achieving the verification speed-up.