To utilize variation of the consumed power of a system with the variation of the number of operating computers or processors and variation in usage rate of the processors, measure the consumed power, and perform volume accounting of computer usage fee based on the measured power value.
The volume accounting device 20 measures the power value supplied to the computers 11 with a measuring section 32. When a flag 33 indicating the state under volume accounting is in the OFF state, the volume accounting device registers the measured power value as new standby power value in a reference data table 36. When the flag 33 is in the ON state, the volume accounting device calculates a usage power value by subtracting the standby power value registered in the reference data table 36 from the measured power value, registers it in a usage amount table 35, calculates usage power by accumulating the usage power value registered in the usage amount table 35, converts the power usage amount into the corresponding computer usage fee, and accounts it.
Naoki Shimosaka
Yasuhisa Tanizawa