Full-chip scan data can be advantageously used during design planning to minimize top-level scan wires and scan feedthroughs. The scan cells can be reordered using a modified cost function to promote connecting all scan cells in one plan group before crossing to a scan cell in another plan group. The modified cost function can take into account penalty parameters. The penalty parameters can include at least one of: membership in a plan group or a top-level physical hierarchy, size of a plan group, FLOATING/ORDERED scan element in scan data, location of endpoints of an ORDERED list, location of endpoints of a macro, and membership in a plan group containing a STOP point. Scan data, at the block-level and at the top-level, can be automatically updated to reflect the plan groups and optimized scan chains.