A storage management device arranged to manage a storage apparatus in which a plurality of volumes are included and which is arranged to send and receive data via transmission resources to or from a server arranged to execute an application for reading or writing the data, the volumes being grouped into management groups in each of which the bandwidth is changed, the management group being specified by a combination of the storage apparatus and the transmission resources, having the volumes, being integrally managed by the storage apparatus, and adjusting the bandwidth of the volumes that are included in a single management group by using a single set command, the storage management device comprising: a setting unit arranged to set a target value of response time to some or all of the volumes; a monitoring unit arranged to monitor the load factor of the transmission resources; and a bandwidth management unit arranged to: specify a first transmission resource on the basis of the load factor of the transmission resources; calculate a total sum of the absolute values of differences between the target value and a measured response time of the volumes in each of which the target value is set and that is included in one of the management groups with respect to each management group, the measured response time being an actual response time of volumes; extract the volumes included in a predetermined number of groups in an order of the groups in which the total sum is larger, among the volumes that use the specified transmission resource; and reserve, if the target value of the response time of a target set volume in the extracted volumes is longer than the measured time of the target set volume, a reduction of the bandwidth of the target set volume and an expansion of the bandwidth of a non target set volume in the extracted volumes and reserve, if the target value of the response time is shorter than the measured response time, an expansion of the bandwidth of the target set volume and a reduction of the bandwidth of the non target set volume, create a set command for each of the extracted volumes from reservation of expansion and reduction for the expansion or the reduction of the bandwidth, and instruct a bandwidth limiting unit in the storage apparatus to adjust the bandwidth using the created set command. a setting unit arranged to set a target value of response time to some or all of the volumes; a monitoring unit arranged to monitor the load factor of the transmission resources; and a bandwidth management unit arranged to: specify a first transmission resource on the basis of the load factor of the transmission resources; calculate a total sum of the absolute values of differences between the target value and a measured response time of the volumes in each of which the target value is set and that is included in one of the management groups with respect to each management group, the measured response time being an actual response time of volumes; extract the volumes included in a predetermined number of groups in an order of the groups in which the total sum is larger, among the volumes that use the specified transmission resource; and reserve, if the target value of the response time of a target set volume in the extracted volumes is longer than the measured time of the target set volume, a reduction of the bandwidth of the target set volume and an expansion of the bandwidth of a non target set volume in the extracted volumes and reserve, if the target value of the response time is shorter than the measured response time, an expansion of the bandwidth of the target set volume and a reduction of the bandwidth of the non target set volume, create a set command for each of the extracted volumes from reservation of expansion and reduction for the expansion or the reduction of the bandwidth, and instruct a bandwidth limiting unit in the storage apparatus to adjust the bandwidth using the created set command. specify a first transmission resource on the basis of the load factor of the transmission resources; calculate a total sum of the absolute values of differences between the target value and a measured response time of the volumes in each of which the target value is set and that is included in one of the management groups with respect to each management group, the measured response time being an actual response time of volumes; extract the volumes included in a predetermined number of groups in an order of the groups in which the total sum is larger, among the volumes that use the specified transmission resource; and reserve, if the target value of the response time of a target set volume in the extracted volumes is longer than the measured time of the target set volume, a reduction of the bandwidth of the target set volume and an expansion of the bandwidth of a non target set volume in the extracted volumes and reserve, if the target value of the response time is shorter than the measured response time, an expansion of the bandwidth of the target set volume and a reduction of the bandwidth of the non target set volume, create a set command for each of the extracted volumes from reservation of expansion and reduction for the expansion or the reduction of the bandwidth, and instruct a bandwidth limiting unit in the storage apparatus to adjust the bandwidth using the created set command.