A bone anchoring device includes an anchoring element having a shank to be anchored in a bone or a vertebra, a rod for connecting at least two anchoring elements, the rod being made of an elastic material. Each tool is separately movable relative to the housing between a retracted position located within the housing and an extended position projecting outwardly from the housing. Corresponding to the process completion prediction time, a cassette that contains a plurality of unprocessed wafers for one lot is accepted.