A computer system according to the present invention is provided with a request classification tool generating a request classification log which describes a number of web requests handled by the computer system for each predetermined measurement period and for each type of the web requests; a system unification processing tool for generating a system log which describes a status of resources of the computer system for the each predetermined measurement period; and resource usage status analysis tool. The resource usage status analysis tool calculates a request handling resource usage amount per web request by using the request classification log and the system log for each type of the web requests, the request handling resource usage amount being a usage amount of resources used for handling the web requests per web request.