1. A management computer for managing a plurality of computers to be managed, comprising: storage resources holding a management program; and a processor for executing the management program, wherein the storage resources include: (1) topologies indicating relationships among a plurality of managed objects, which are the plurality of managed computers or a plurality of components included in the plurality of managed computers; (2) event propagation models, one of the event propagation models indicating that events of type A which occur to managed objects of type 1 cause events of type B to occur to management objects of type 2; and (3) causality information including one or more causal relations, wherein one of the causal relations indicates that a first event of type A which occurs to a first managed object of type 1 causes a second event of type B to occur to a second managed object of type 2, and wherein the management program is configured for the processor to: (A) detect an event relating to a problem that has occurred to a managed object; (B) determine whether an applicable causal relation to be used in analysis of the detected event has been created in the causality information; (C) perform, in a case where the processor determines that the applicable causal relation has not been created in (B), on-demand expansion based on one of the topologies and one of the event propagation models to create the applicable causal relation in the causality information; and (D) analyze the detected event using the applicable causal relation.