Even when a configuration in which instances of plural kinds of storage management software having equivalent functions are arranged to cooperatively manage a large-scale storage system is adopted, to prevent occurrence of a management inoperability and configuration information inconsistency and enable the same management operation and information reference as those performed when all management target objects are managed by a single instance. In the present invention, a representative management computer serving as a representative among management computers is determined. The representative management computer collects, from storage apparatuses and host computers, information concerning the management target objects and configuration summary information including a relation type among the objects and determines, on the basis of the configuration summary information, management target objects which each of the management computers should take charge of.