If a failure occurs in physical resources constituting a virtual volume, a management server device is notified of information required by a user. A computer system includes a server device for managing a plurality of virtual volumes, a storage apparatus having a storage unit equipped with a plurality of storage devices, and a controller for controlling data input to, or output from, the storage unit, a management server device which is an access target of a user terminal, and an event management device for managing an event(s) generated by the server device or the storage apparatus, wherein when the event management device receives the event, it judges the content of the event and identifies a virtual volume to be affected by the event; and if a service level that should be satisfied by the identified virtual volume is defined for the identified virtual volume, the event management device identifies, based on the content of the received event, whether an incident in violation of the service level has occurred or not, and then notifies the management server device of the identified content as an event based on an event filter.