Patent ID: 8738625

Claim:
A log management system for analyzing and managing a log acquired in a computer, the log management system comprising: a processor; and a storage device, wherein the storage device stores a log of the computer; wherein the processor is configured to generate a plurality of log groups each formed of a plurality of log records with reference to the log stored in the storage device; wherein the processor is configured to identify active periods, in each of which a display area is active, in the plurality of log groups; wherein the processor is configured to compare a start-to-end period, which is a period from a start time to an end time of a reference log group selected from the plurality of log groups, with active periods of subject log groups other than the reference log group individually and to identify one or more subject log groups having an active period included in the start-to-end period; wherein the processor is configured to determine individually whether to include the identified one or more subject log groups in a same first cluster including the reference log group, based on an active period length of each of the identified one or more subject log groups within the start-to-end period; wherein the processor is configured to calculate individually ratios of the active period lengths of the identified one or more subject log groups within the start-to-end period to a total active period length of the reference log group; wherein, when any of the calculated ratios is equal to or higher than a predetermined value, the processor is configured to determine to include the identified subject log group in the first cluster; wherein the processor is configured to calculate individually total active period lengths of all the log groups included in the first cluster; and wherein the processor is configured to estimate a working time spent to a task of the first cluster from the calculated total active period lengths of all the log groups.