PURPOSE: To grasp the actual working state of a terminal and to improve the system operating efficiency by totalizing the on-line using time and the off-line using time separately from each other for execution of a task proper to a user within an operating time of the terminal in a fixed period.

CONSTITUTION: All process executing state data which are generated and executed up to the current time outputted from an accounting processing part 1 are received at each time set optionally and previously. Then these received data are rearranged in terms of the time series, and the operating time is calculated. The system process executing time is deleted based on a system process name register table 7a, and the executing time proper to a user is calculated for each user process. Furthermore the overlapping time bands are deleted and a real using time band of a user process is calculated for production of a real using time band data 6. Then the data 6 are transferred to a host computer in each fixed periods. Thus the user can grasp the using state of a terminal.