Continued technology scaling exacerbates the incidence of degradation and failure in integrated circuits due to mechanisms such as oxide breakdown, negative bias temperature instability and electromigration. This work analyzes the impact of different factors on lifetime distributions for the oxide breakdown effect using a novel monte carlo approach based upon the percolation model and BSIM4. Results of the analysis of oxide failure distributions are used to explore real-time lifetime projection and the use of in-situ monitoring circuits. Under an ideal sensor assumption, the work shows that 500-1000 sensors would be needed to provide lifetime projections with error under 8-10%.