In invariant relation analysis, a correlation model having high abnormality detection ability is generated. A system analysis device (100) includes a correlation function storage unit (1022), and a correlation function extraction unit (1023). The correlation function storage unit (1022) stores a plurality of candidates for a correlation function expressing a correlation for each pair of metrics in a system. The correlation function extraction unit (1023) extracts a correlation function from a plurality of candidates for a correlation function as a correlation function for each pair of metrics, on the basis of a detection sensitivity indicating a likelihood of correlation destruction caused at the time of abnormality of a metric associated with a correlation function.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A system analysis device comprising: a correlation function storage unit which stores plurality of candidates for a correlation function that represents a correlation of a pair of metrics in a system; and a correlation function extraction unit which extracts one correlation function as the correlation function for the pair of metrics from the plurality of candidates for the correlation function on the basis of a detection sensitivity indicating a likelihood of correlation destruction caused at the time of abnormality of a metric associated with a correlation function. 2. The system analysis device according to claim 1, wherein the correlation function extraction unit extracts, as the correlation function for the pair of metrics, a correlation function exhibiting the detection sensitivity higher than the detection sensitivities of the other correlation functions from the plurality of candidates for the correlation function. 3. The system analysis device according to claim 1, wherein the correlation function for the pair of metrics is a function that predicts a value of one of the metrics of the pair based on time series of both the metrics of the pair, or time series of the other metric of the pair, and the detection sensitivity of the correlation function to the metric associated with the correlation function is determined so as to increase in accordance with a coefficient to be multiplied by the metric in the correlation function. 4. The system analysis device according to claim 3, wherein the detection sensitivity of the correlation function to the metric associated with the correlation function is further determined so as to decrease in accordance with a prediction error of the correlation function. 5. The system analysis device according to claim 1, wherein the correlation function extraction unit extracts the correlation function from correlation functions exhibiting a prediction accuracy equal to or higher than a predetermined value in the plurality of candidates for the correlation function. 6. The system analysis device according to claim 1, further comprising: a correlation destruction detection unit which detects correlation destruction in a correlation of the pair of metrics by using the extracted correlation function for the pair of metrics; and an abnormality cause extraction unit which extracts a metric of candidates for abnormality cause on the basis of the correlation for which the correlation destruction is detected. 7. A system analysis method comprising: storing a plurality of candidates for a correlation function that represents a correlation of a pair of metrics in a system; and extracting one correlation function as the correlation function for the pair of metrics from the plurality of candidates for the correlation function on the basis of a detection sensitivity indicating a likelihood of correlation destruction caused at the time of abnormality of a metric associated with a correlation function. 8. The system analysis method according to claim 7, wherein, when extracting the correlation function for the pair of metrics, as the correlation function for the pair of metrics, extracting a correlation function exhibiting the detection sensitivity higher than the detection sensitivities of the other correlation functions from the plurality of candidates for the correlation function. 9. The system analysis method according to claim 7, wherein the correlation function for the pair of metrics is a function that predicts a value of one of the metrics of the pair based on time series of both the metrics of the pair, or time series of the other metric of the pair, and the detection sensitivity of the correlation function to the metric associated with the correlation function is determined so as to increase in accordance with a coefficient to be multiplied by the metric in the correlation function. 10. The system analysis method according to claim 9, wherein the detection sensitivity of the correlation function to the metric associated with the correlation function is further determined so as to decrease in accordance with a prediction error of the correlation function. 11. The system analysis method according to claim 7, wherein, when extracting the correlation function for the pair of metrics, extracting the correlation function from correlation functions exhibiting a prediction accuracy equal to or higher than a predetermined value in the plurality of candidates for the correlation function. 12. The system analysis method according to claim 7, further comprising: detecting correlation destruction in a correlation of the pair of metrics by using the extracted correlation function for the pair of metrics; and extracting a metric of candidates for abnormality cause on the basis of the correlation for which the correlation destruction is detected. 13. A non-transitory computer readable storage medium recording thereon a program, causing a computer to perform a method comprising: storing a plurality of candidates for a correlation function that represents a correlation of a pair of metrics in a system; and extracting one correlation function as the correlation function for the pair of metrics from the plurality of candidates for the correlation function on the basis of a detection sensitivity indicating a likelihood of correlation destruction caused at the time of abnormality of a metric associated with a correlation function. 14. The non-transitory computer readable storage medium recording thereon the program according to claim 13, wherein, when extracting the correlation function for the pair of metrics, as the correlation function for the pair of metrics, extracting a correlation function exhibiting the detection sensitivity higher than the detection sensitivities of the other correlation functions from the plurality of candidates for the correlation function. 15. The non-transitory computer readable storage medium recording thereon the program according to claim 13, wherein the correlation function for the pair of metrics is a function that predicts a value of one of the metrics of the pair based on time series of both the metrics of the pair, or time series of the other metric of the pair, and the detection sensitivity of the correlation function to the metric associated with the correlation function is determined so as to increase in accordance with a coefficient to be multiplied by the metric in the correlation function. 16. The non-transitory computer readable storage medium recording thereon the program according to claim 15, wherein the detection sensitivity of the correlation function to the metric associated with the correlation function is further determined so as to decrease in accordance with a prediction error of the correlation function. 17. The non-transitory computer readable storage medium recording thereon the program according to claim 13, wherein, when extracting the correlation function for the pair of metrics, extracting the correlation function from correlation functions exhibiting a prediction accuracy equal to or higher than a predetermined value in the plurality of candidates for the correlation function. 18. The non-transitory computer readable storage medium recording thereon the program according to claim 13, further comprising: detecting correlation destruction in a correlation of the pair of metrics by using the extracted correlation function for the pair of metrics; and extracting a metric of candidates for abnormality cause on the basis of the correlation for which the correlation destruction is detected. 19. A system analysis device comprising: a correlation function storage means for storing a plurality of candidates for a correlation function that represents a correlation of a pair of metrics in a system; and a correlation function extraction means for extracting one correlation function as the correlation function for the pair of metrics from the plurality of candidates for the correlation function on the basis of a detection sensitivity indicating a likelihood of correlation destruction caused at the time of abnormality of a metric associated with a correlation function.