1. An information processing apparatus connectable to a plurality of devices of different types via a network, the information processing apparatus comprising: a memory; and a processor configured to: receive, from each of the plurality of devices, master data of management information when the each of the plurality of devices is connected to the information processing apparatus for a first time; store, in the memory, the master data of the management information of the each of the plurality of devices, the master data including at least item identification information of each management item included in the management information and data format of the each management item corresponding to the each of the plurality of devices; store, in the memory, a first conversion rule for converting the management information into management information in a first common data format common to the plurality of devices; receive, from the each of the plurality of devices, the management information of the each of the plurality of devices in a data format corresponding to the each of the plurality of devices; and convert the management information thus received into the management information in the first common data format based on the master data of the management information and the first conversion rule.