A method for monitoring software usage for an application installed in a computer system. The computer system determines whether a change has occurred in a set of files stored in a set of directories for the application in a file system between inventory scans of the file system. The set of the files is associated with the application and the set of the files changes when the application is used. A usage metric for the application is adjusted by the computer system to indicate a use of the application when the change has occurred in the set of the files, increasing accuracy, by the computer system, in identifying application usage.