Kits and their parts
A kit is now one item with its parts listed. Say once what is in it, such as the DNeasy Blood & Tissue Kit's spin columns and buffers, then receive a box and every part sits on the kit lot. The box reads in uses, 40 of 50, and names the part that will run out first.
Record use takes each part's share of the uses you record. You can correct one part on its own, split a box across places and finish it when it is done. Alerts and experiment templates count a kit in uses, so a run that needs four preps knows whether the box has them, and Analytics show what each use costs.