A large-scale computer system including a plurality of nodes is controlled to improve its system performance without aggregating data in a single site. There is provided a computer system including a plurality of computers, wherein a processor: detects a trigger to calculate a control value for controlling a process to be performed by the computer; identifies a target computer for which an evaluation value is obtained; calculates the evaluation value of its own computer; obtains the evaluation value from the target computer; calculates a first point using at least one of the evaluation value of its own computer and the evaluation value of the target computer; obtains a second point from the target computer; calculates the control value using the first point and the second point; and controls the process performed by the computer based on the control value.