- We propose a dynamic test compaction procedure to generate high-quality test patterns for path delay faults. While the proposed procedure generates a compact two-pattern test set for paths selected by a path selection criterion, the generated test set would detect not only faults on the selected paths but also faults on many unselected paths. Hence both high test quality by detecting untargeted faults and test cost reduction by reducing test patterns can be achieved. Experimental results show that the proposed procedure could generate a compact test set that detect many untargeted path delay faults certainly, compared with the static test compaction method previously proposed in [15].