Managing performance data includes receiving a record of an agreement between a first party and a second party, where the second party is either a supplier or an alliance partner. The cavity length of the device is 1,200 m or more. Then, the virtual device management server selects a virtual device server for providing a Web service corresponding to the processing request on the basis of server information, the processing request, and location information about the printer to thereby assign the selected virtual device server to the printer. 5 mass % to 20 mass %; and the chromate film layer has Cr attached thereto in an amount of from 1.