A system includes a plurality of semiconductor processing tools; a carrier purge station; a carrier repair station; and an overhead transport (OHT) loop for transporting one or more substrate carriers among the plurality of semiconductor processing tools, the carrier purge station, and the carrier repair station. The carrier purge station is configured to receive a substrate carrier from one of the plurality of semiconductor processing tools, purge the substrate carrier with an inert gas, and determine if the substrate carrier needs repair. The carrier repair station is configured to receive a substrate carrier to be repaired and replace one or more parts in the substrate carrier.