These are on the following page, labelled PFD-1 through PFD-4. Look first at PFD-1, which illustrates the processes and linkages for building the three drills: DR12, DR54, and DR11. That suggests that the three drill models, though they may have different features, generally follow the same work steps. Next, On PFD-2 for orbital sanders OS31 and OS32, start at the final process “Pack” and look upstream: identical through “Test” and “Final Assembly”, with one difference above. Continue to study PFD-3 and PFD-4, looking for commonalities and differences.