COMPUTER SYSTEM AND PLAN EVALUATION METHOD

A computer system is coupled to a first database and a second database, the first database storing model information defining a model, the second database storing history data indicating a plan developed in a past. The computer system generates, in a case of receiving an evaluation query including evaluation plan data that indicates an evaluation target plan, a plurality of pieces of the pair data each of which is a pair of the evaluation plan data and the history data; obtains a plurality of prediction results by inputting the plurality of pieces of the pair data to the model; select a piece of the history data that has an evaluation index small in difference from the evaluation index of the evaluation target plan based on the plurality of prediction results; and output the selected piece of the history data.