An operation management method in an information processing system having a plurality of information processing devices (110a-b; 220a-b; 1320a-b; 2120a-d) and cooling equipment (210a-b; 1310a-b; 2110a-b) and deciding workload allocation to the information processing devices with an operation management device previously storing specification information (310-380; 1410-1480) of each information processing device, the method comprising: obtaining, by experiments or simulations, at least one device-specific coefficient of performance (940; 1640) relating to each information processing device (110a-b; 220a-b; 1320a-b; 2120a-d), based on heat generated from the information processing devices and electric power of the cooling equipment (210a-b; 1310a-b; 2110a-b) for exchange of the heat; characterized by: obtaining index values (1120, 1130; 1820) indicating performances of each information processing device (110a-b; 220a-b; 1320a-b; 2120a-d) per unit power consumption relating to total power consumption of power consumption of each information processing device at previously specified resource utilization ratio for each information processing device, respectively, and power consumption of the cooling equipment (210a-b; 1310a-b; 2110a-b) for cooling heat to be generated from each information processing device corresponding to the power consumption of each information processing device, based only on the previously stored specification information (310-380; 1410-1480) of each information processing device and the at least one device-specific coefficient of performance (940; 1640) relating to each information processing device; and deciding workload allocation by allocating workloads (111a-d; 1211a-d) based on the index values (1120, 1130; 1820). obtaining, by experiments or simulations, at least one device-specific coefficient of performance (940; 1640) relating to each information processing device (110a-b; 220a-b; 1320a-b; 2120a-d), based on heat generated from the information processing devices and electric power of the cooling equipment (210a-b; 1310a-b; 2110a-b) for exchange of the heat; characterized by: obtaining index values (1120, 1130; 1820) indicating performances of each information processing device (110a-b; 220a-b; 1320a-b; 2120a-d) per unit power consumption relating to total power consumption of power consumption of each information processing device at previously specified resource utilization ratio for each information processing device, respectively, and power consumption of the cooling equipment (210a-b; 1310a-b; 2110a-b) for cooling heat to be generated from each information processing device corresponding to the power consumption of each information processing device, based only on the previously stored specification information (310-380; 1410-1480) of each information processing device and the at least one device-specific coefficient of performance (940; 1640) relating to each information processing device; and deciding workload allocation by allocating workloads (111a-d; 1211a-d) based on the index values (1120, 1130; 1820). obtaining index values (1120, 1130; 1820) indicating performances of each information processing device (110a-b; 220a-b; 1320a-b; 2120a-d) per unit power consumption relating to total power consumption of power consumption of each information processing device at previously specified resource utilization ratio for each information processing device, respectively, and power consumption of the cooling equipment (210a-b; 1310a-b; 2110a-b) for cooling heat to be generated from each information processing device corresponding to the power consumption of each information processing device, based only on the previously stored specification information (310-380; 1410-1480) of each information processing device and the at least one device-specific coefficient of performance (940; 1640) relating to each information processing device; and deciding workload allocation by allocating workloads (111a-d; 1211a-d) based on the index values (1120, 1130; 1820).