In the past few years, it has become clear that fabrication variability is one of the most important challenge that needs to be addressed for keeping the semiconductor industry profitable. Fabrication variability imposes an underlying uncertainty on the design process of VLSI chips making several parameters random. Therefore, the old way of doing design needs to be overhauled for considering this randomness. This implies that VLSI CAD needs to incorporate probabilistic models for capturing uncertainty and stochastic optimization for controlling the design decision variables. Several challenges need to be addressed before this is made possible...