A method may include: specifying a random nets credit (RNC) statistic for nets subject to random noise in a static timing analysis of an initial integrated circuit (IC) design; calculating an upper bound for a delta delay of each net using the RNC statistic; identifying each net with a delta delay that exceeds the upper bound; identifying all nets including fan-in and fan-out cones connected to each net that exceeds the upper bound and performing a higher accuracy timing analysis for all nets that are marked. Using the upper bound for each delta delay of the nets subject to ransom noise, the delta delay of each net subject to a non-random noise, and the delta delay for all identified nets, to adjust the initial IC design, to close timing and generate a final IC design.