1. A monitoring data analyzing apparatus comprising: a data accumulating section configured to accumulate log data including monitoring data in a monitoring target system set as a target of performance management; a data classifying section configured to classify the log data into a plurality of groups on the basis of characteristics of use status data included in the log data and indicating statuses of use of components of the monitoring target system; and a regression-model generating section configured to execute a regression analysis of the log data and generate a regression model for each of the groups.