1. A management computer for managing a plurality of physical or logical components which configure a computer system, comprising: storage resources holding a management program; and a processor for executing the management program, wherein the storage resources include: a topology information indicating relationships among the plurality of components; an event propagation model indicating a set of conditional expressions which are consisted of causal events and analysis results and are represented by a type of the components as a management target; and a causality information including a plurality of causal relations which are the conditional expressions relevant to a specified component as a management target; wherein the management program is configured for the processor to: detect an event relating to a problem that has occurred to a managed component; determine whether or not a first causal relation to be used in analysis of the detected event has been created in the causality information; perform an on-demand expansion based on one of the topologies and one of the event propagation models to create the first causal relation in the causality information in case where the processor determines that the first causal relation has not been created or is being created in the process of former determining; and analyze the detected event using the first causal relation.