An operation management apparatus comprising: a correlation model generation means for generating a correlation model including one or more correlation functions each indicating a correlation between two different metrics among a plurality of metrics of a system, the metric being a performance index of the system, the correlation function being a function which estimates, from a value of one metric in two different metrics, a value of the other metric in the two different metrics; a configuration change detection means for detecting whether a configuration change of the system has occurred or not; wherein the generation model generation means are adapted to, when a configuration change is detected, generate a correlation model based on the performance information in a predetermined modeling period collected after the configuration change detection; and a fault analysis means for identifying a fault cause of the system using the correlation model which is generated based on measured values of the plurality of metrics after the configuration change of the system when the configuration change of the system is detected by the configuration change detection means, and for setting the generated correlation model as correlation model to be used wherein destruction of a correlation included in the correlation model is defined as correlation destruction, wherein the fault analysis means is configured to identify the fault cause of the system by comparing status of correlation destruction detected for newly measured values of the plurality of metrics and a correlation destruction pattern indicating status of correlation destruction at time of a fault of the system occurred in the past, and wherein the correlation destruction is detected if a difference between a value estimated by inputting a newly inputted value of one metric into the correlation function and a newly inputted value of the other metric is equal to or greater than a predetermined value, further comprising a correlation destruction pattern updating means for correcting the correlation destruction pattern based on the correlation model used after the configuration change when the configuration change of the system is detected by the configuration change detection means, and wherein the fault analysis means is configured to identify the fault cause of the system by using the corrected correlation destruction pattern when the configuration change of the system is detected by the configuration change detection means. a correlation model generation means for generating a correlation model including one or more correlation functions each indicating a correlation between two different metrics among a plurality of metrics of a system, the metric being a performance index of the system, the correlation function being a function which estimates, from a value of one metric in two different metrics, a value of the other metric in the two different metrics; a configuration change detection means for detecting whether a configuration change of the system has occurred or not; wherein the generation model generation means are adapted to, when a configuration change is detected, generate a correlation model based on the performance information in a predetermined modeling period collected after the configuration change detection; and a fault analysis means for identifying a fault cause of the system using the correlation model which is generated based on measured values of the plurality of metrics after the configuration change of the system when the configuration change of the system is detected by the configuration change detection means, and for setting the generated correlation model as correlation model to be used wherein destruction of a correlation included in the correlation model is defined as correlation destruction, wherein the fault analysis means is configured to identify the fault cause of the system by comparing status of correlation destruction detected for newly measured values of the plurality of metrics and a correlation destruction pattern indicating status of correlation destruction at time of a fault of the system occurred in the past, and wherein the correlation destruction is detected if a difference between a value estimated by inputting a newly inputted value of one metric into the correlation function and a newly inputted value of the other metric is equal to or greater than a predetermined value, further comprising a correlation destruction pattern updating means for correcting the correlation destruction pattern based on the correlation model used after the configuration change when the configuration change of the system is detected by the configuration change detection means, and wherein the fault analysis means is configured to identify the fault cause of the system by using the corrected correlation destruction pattern when the configuration change of the system is detected by the configuration change detection means.