A device management method of a device management apparatus that manages information of devices installed in a home, includes: acquiring electric power consumption per unit time in predetermined time intervals, for each of branch circuits of a power distribution board to which the devices can be connected; estimating existence of the devices connected to the branch circuit, based on change of electric power consumption over time, per unit time; condition determining whether or not an estimated device, which is a device regarding which existence has been estimated in the estimating, satisfies a predetermined condition; and transmitting inquiry information to a user in accordance with the predetermined condition, only in a case where determination is made in the condition determining that the estimated device satisfies the predetermined condition.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A device management method of a device management apparatus that manages information of devices installed in a home, the method comprising: acquiring electric power consumption per unit time in predetermined time intervals, for each of branch circuits of a power distribution board to which the devices can be connected; estimating existence of the devices connected to the branch circuit, based on change of electric power consumption over time, per unit time; condition determining whether or not an estimated device, which is a device regarding which existence has been estimated in the estimating, satisfies a predetermined condition; and transmitting inquiry information to a user in accordance with the predetermined condition, only in a case where determination is made in the condition determining that the estimated device satisfies the predetermined condition. 2. The device management method according to claim 1, wherein, in the condition determining, if determination is made that the estimated device is a newly-installed device that has been newly installed in the home, determination is made that the predetermined condition is not satisfied. 3. The device management method according to claim 2, wherein, in the condition determining, management information is referenced in which devices existing within the home and the branch circuits are correlated by the branch circuits, and in a case where the estimated device is not registered in the management information, determination is made that the estimated device is the newly-installed device. 4. The device management method according to claim 3, wherein the condition determining includes first device determining where determination is made regarding whether or not another already-existing device has been correlated with a branch circuit to which the newly-installed device has already been correlated in the management information, second device determining where, in a case that determination has been made in the first device determining that the already-existing device has been correlated with a branch circuit to which the newly-installed device has been correlated, determination is made regarding whether or not the newly-installed device is a device that independently uses the branch circuit as a dedicated branch circuit, and third device determining where, in a case that determination has been made in the second device determining that the newly-installed device uses the dedicated branch circuit, determination is made that the already-existing device has been replaced by the newly-installed device, wherein, in a case where determination is made in the third device determining that the already-existing device has been replaced by the newly-installed device, determination is made in the condition determining that the predetermined condition is not satisfied. 5. The device management method according to claim 1, wherein the condition determining includes new installation determining where management information is referenced in which devices existing within the home and the branch circuits are correlated by the branch circuits, and in a case where the estimated device is not registered in the management information, determination is made that the estimated device is a newly-installed device that has been newly installed in the home, first device determining where determination is made regarding whether or not another already-existing device has already been correlated with a branch circuit to which the newly-installed device has been correlated in the management information, and second device determining where, in a case that determination has been made in the first device determining that the already-existing device has already been correlated with a branch circuit to which the newly-installed device has been correlated in the management information, determination is made regarding whether or not the newly-installed device is a device that shares the branch circuit as a shared branch circuit with other devices, wherein, in the condition determining, if determination is made in the second device determining that the newly-installed device uses the shared branch circuit, determination is made that the estimated device satisfies the predetermined condition, wherein, in the transmitting, information is transmitted to the user for confirmation of whether or not the already-existing device exists, as the inquiry information, and wherein, in the condition determining, determination is made whether or not to update information relating to the already-existing device in the management information, in accordance with the content of the response as to the inquiry information. 6. The device management method according to claim 1, wherein, in the condition determining, if determination is made that the estimated device is a relocated device that has been relocated from a first location corresponding to a first branch circuit to which the estimated device had already been connected, to a second location corresponding to a second branch circuit, determination is made that the estimated device satisfies the predetermined condition. 7. The device management method according to claim 6, wherein, in the condition determining, management information is referenced in which devices existing within the home and the branch circuits are correlated by the branch circuits, and in a case where the estimated device estimated to be connected to the second branch circuit in the estimating exists in the management information, and also is correlated with the first branch circuit that is different from the second branch circuit, determination is made that the estimated device is the relocated device. 8. The device management method according to claim 1, wherein the condition determining includes relocation determining where management information is referenced in which devices existing within the home and the branch circuits are correlated by the branch circuits, and in a case where the estimated device estimated to be connected to the first branch circuit in the estimating exists in the management information, and also is correlated with the second branch circuit that is different from the first branch circuit, determination is made that the estimated device is a relocated device that has been relocated from the first location of connection to the second branch circuit to the second location of connection to the first branch circuit, and device determining where, in a case that the estimated device is determined in the relocation determining to be the relocated device, determination is made regarding whether or not the relocated device is a device that independently uses the branch circuit as a dedicated branch circuit, wherein, in the condition determining, if determination is made in the device determining that the relocated device does not use the dedicated branch circuit, determination is made that the estimated device satisfies the predetermined condition, and wherein, in the transmission, information is transmitted to the user for confirmation regarding whether or not the relocation of the relocated device from the first location to the second location is temporary, as the inquiry information. 9. The device management method according to claim 1, wherein the condition determining includes relocation determining where management information is referenced in which devices existing within the home and the branch circuits are correlated by the branch circuits, and in a case where the estimated device estimated to be connected to the first branch circuit in the estimating exists in the management information, and also is correlated with the second branch circuit that is different from the first branch circuit, determination is made that the estimated device is a relocated device that has been relocated from the first location of connection to the second branch circuit to the second location of connection to the first branch circuit, and device determining where, in a case that the estimated device is determined in the relocation determining to be the relocated device, determination is made regarding whether or not the relocated device is a device that independently uses the branch circuit as a dedicated branch circuit, and wherein, if determination is made in the device determining that the relocated device uses the dedicated branch circuit, determination is made in the condition determining that the estimated device does not satisfy the predetermined condition. 10. The device management method according to claim 1, wherein, in the condition determining, in a case where the estimated device has not been used for a predetermined period or longer, determination is made that the predetermined condition is satisfied. 11. The device management method according to claim 10, wherein, in the condition determining, management information is referenced in which devices existing within the home and the branch circuits are correlated by the branch circuits, and in a case where the estimated device is registered in the management information and also existence thereof has not been estimated in the estimating for a predetermined period or longer, determination is made that the estimated device has not been used for the predetermined period or longer. 12. The device management method according to claim 10, wherein, in a case where determination is made in the condition determining that the estimated device has not been used for the predetermined period or longer, information is transmitted in the transmitting to prompt the user to inspect the estimated device. 13. The device management method according to claim 1, wherein, in the condition determining, in a case where the estimated device has been continuously used for a predetermined period or longer, determination is made that the predetermined condition is satisfied. 14. The device management method according to claim 13, wherein, in the condition determining, management information is referenced in which devices existing within the home and the branch circuits are correlated by the branch circuits, and in a case where the estimated device is registered in the management information and also existence thereof has been continuously estimated in the estimating for a predetermined period or longer, determination is made that the estimated device has been continuously used for the predetermined period or longer. 15. The device management method according to claim 13, wherein, in a case where determination is made in the condition determining that the estimated device has been continuously used for the predetermined period or longer, information is transmitted in the transmitting to prompt the user to confirm the state of a part used in the estimated device. 16. The device management method according to claim 1, wherein, in the estimating, information of change in electric power consumption over time, per unit time in accordance with operation of the device, is referenced, and the referenced information of change over time is compared with change over time of electric power consumption per unit time at the branch circuit acquired in the acquiring at predetermined time intervals, thereby estimating the existence of the device connected to the branch circuit. 17. A device management method of a device management apparatus that manages information of devices installed in a home, the method comprising: first acquiring electric power consumption per unit time in predetermined time intervals, for each of branch circuits of a power distribution board to which the devices can be connected; second acquiring information relating to content of an operation performed as to the device, and clock time at which the operation was performed; estimating a branch circuit to which the device, to which the operation was performed, is connected, based on change over time of the electric power consumption per unit time in a predetermined time including the clock time at which the operation was performed as to the device; determining whether or not the device to which the operation was performed satisfies the predetermined condition, based on the change over time of the electric power consumption per unit time; and transmitting inquiry information to a user in accordance with the predetermined condition, only in a case where determination is made in the determining that the device to which the operation was performed satisfies the predetermined condition. 18. A device management apparatus that manages information of devices installed in a home, the device management apparatus comprising: an acquisition unit that acquires electric power consumption per unit time in predetermined time intervals, for each of branch circuits of a power distribution board to which the devices can be connected; an estimating unit that estimates existence of the devices connected to the branch circuit, based on change of electric power consumption over time, per unit time; a determining unit that determines whether or not an estimated device, which is a device regarding which existence has been estimated by the estimating unit, satisfies a predetermined condition; and a transmission unit that transmits inquiry information to a user in accordance with the predetermined condition, only in a case where determination is made by the determining unit that the estimated device satisfies the predetermined condition.