In a multi-tenancy information processing system, a necessary setting change item and a target NW device are specified at the time of changing a configuration of a virtual machine of a tenant. A management server 116 includes a device management table 352 for each tenant and each segment, in which an NW setting item set for a network (NW) device is stored for each of the NW devices corresponding to the segment of the tenant, in advance. The management server 116 receives a configuration change request including type information on a request representing addition, deletion, or movement of the virtual machine, an identifier of a target tenant, and an identifier of a target segment.