The present invention is applied to a system comprised of large number of hydraulic excavators 1 deployed at construction sites and a base station 16. Each hydraulic excavator 1 is provided with a storage unit (memory 402), a control unit (CPU 401) for executing the work operation and receiving as input a quantitative machine status relating to the work operation, and a communications device 42. The base station 16 is provided with a communications device 16a, a management server 17 for identifying the serial number of the hydraulic excavator 1 and transferring information, and a database 18 for storing various information. The control unit of the hydraulic excavator 1 and the management server 17 of the base station 16 transfer information. With this system configuration, the control unit measures the duration during which the quantitative machine status satisfies a predetermined condition and stores it in the storage unit and transmits the measurement data of the duration to the management server 17 of the base station 16 conditional on the power input key being in the off position, while the management server 17 receives the measurement data of the duration and calculates the cumulative operating time. Further, the quantitative machine status and various event data stored in the storage unit of the hydraulic excavator 1 are sent to the base station 1, while the management server of the base station 16 stores the quantitative machine status and various event data in the database 18 by a predetermined format.