SYSTEM, CENTER, PROCESSING METHOD, AND STORAGE MEDIUM

A system includes multiple in-vehicle devices individually mounted on multiple vehicles and a center capable of performing data communication with the multiple in-vehicle devices. Each in-vehicle device transmits vehicle data related to another vehicle device to the center in a first cycle. The center is configured to: store, in a second storage unit, the vehicle data sequentially transmitted from each in-vehicle device; store, in a third storage unit, an index that includes information associated with the vehicle data stored in the second storage unit; perform a first update by adding the received vehicle data to the vehicle data stored in the second storage unit; and perform a second update by adding the index stored in the third storage unit in association with latest one of the vehicle data stored in the second storage unit in a second cycle.