Abstract: A program for improving a netlist of logic nodes and physical placement for an IC. The program (A) identifies critical nodes based on time calculated from a physical placement. The program (B) selects a set of critical nodes and sub-netlists associated with the critical nodes and co-factors critical fan-ins in the sub-netlists. The program remaps the sub-netlists by optimization and dynamically estimates and updates fanout loads. The program returns to step B if the remapped sub-netlist is unacceptable, returns to step A if the remapped sub-netlist is acceptable, and exits at step A when no more critical nodes are identified at step A.