Provided is a technique capable of efficient comprehensive management of a system, even if the system is a large-scale storage system. Management software acquires configuration information of a storage system (computer system) in two stages. In a first stage, the management software acquires only basic information of resources (identifiers of resources, the number of resources, and relationship between the resources) included in storage subsystems, host computers, switches, hubs, and the like. The management software determines a range and timing of acquiring detailed configuration information and necessity of holding the detailed configuration information based on the acquired basic information. In a second stage, the management software acquires the detailed configuration information of an appropriate range at appropriate timing. The management software always holds the basic information, but holds the detailed information only necessary to hold.