An operation management apparatus to improve the accuracy of the estimation of the processing performance needed for the execution environment of the migration-destination, is provides, which is performed in system migration. In an operation management apparatus 100, a correlation model storage unit 112 stores a correlation model indicating a correlation for each pair of one or more metrics in a state of executing a predetermined program in a first processing system. A benchmark performance collection unit 103 collects values of a metric having a correlation with another metric in the correlation model in a state of executing a predetermined benchmark process in the first processing system and a second processing system, respectively. A performance comparison unit 104 calculates and outputs a performance ratio of a metric in the second processing system to the metric in the first processing system, based on the values of the metrics in the state of executing the predetermined benchmark process in the first processing system and the second processing system, respectively.