Arithmetic operation device, plant, arithmetic operation method and program

A plant, comprising:

• an arithmetic operation device that includes a computer system,
• wherein the computer system includes a memory configured to store instructions;
• a storage;
• and a processor configured to execute the instructions to:
• calculate performance of the plant before introduction of a part and the performance of the plant after the introduction of the part for each of combinations of a plurality of loads in the plant and a plurality of atmospheric temperatures around the plant;
• cause the storage to store a data table indicating a percentage of an operating time of the plant for each of the combinations;
• calculate, based on a calculation result in the performance calculation and the data table, how much the performance of the plant is improved compared with the performance before the introduction of the part in a case where the part is introduced and the plant is operated at the percentage indicated by the data table;
• and
• a temperature sensor that is configured to detect the plurality of atmospheric temperatures;
• and
• a power generator that is configured to supply electric power according to a load, wherein a performance of the power generator is changed based on the part included in the plant.