A production system capable of further improving production efficiency and quality. The ring management system includes size measurement unit for measuring size of the ring, first convey unit for moving the ring w whose size has been measured, a first stocker having a plurality of storage positions for storing rings conveyed by the first convey unit, a second convey unit for conveying out the rings from the first stocker means for stacking, and a control unit. The control unit includes memory means for storing the rings size measured by the size measurement means in association with the storage position in the first stocker, first selection means for selecting a ring constituting a stacked ring according to the ring size stored in the memory means, and first instruction means to instruct the second convey unit to convey out the ring selected by the first selection means from the storage position pj in the first stocker.