An operation data recording device 11 mounted at a work machine detects and records operation data of the work machine. The operation data is collected by an external terminal 13 and transmitted from the external terminal 13 to a server 23 located in a remote place. When the operation data is collected by the external terminal 13, a program for the operation data recording device of the work machine is updated to the latest version by the external terminal 13. When transmitting the operation data from the external terminal 13 to the remote server 23, an external terminal program and a program for the operation data recording device stored in the external terminal 13 are updated to the latest versions.