The present invention provides a technique capable of improving use efficiency of storage devices. In this regard, a computer system of the present invention includes: a plurality of storage subsystems; an information processing apparatus coupled to the storage subsystems and including a virtual layer for virtually providing information from the storage subsystems; and the a management system that manages the plurality of storage subsystems and the information processing apparatus. The management system manages, on a memory, configuration information of logical volumes allocated to virtual instances managed on a virtual layer of the information processing apparatus and operation information of hardware resources included in the storage subsystems. The management system evaluates use efficiency of the virtual instances based on the configuration information of the logical volumes and the operation information of the hardware resources and outputs an evaluation result.