1. A metadata management system for performing impact analysis on an IT system comprising: a storage having computer readable program code embodied therewith; a bus connecting the storage to at least one processor; and at least one processor, wherein the at least one processor executes the computer readable program code to implement: a configurable metamodel for modeling metadata that describes assets of an enterprise IT system, the metamodel including meta-classes and meta-properties, wherein the meta-classes and the meta-properties are modeled by imposing binary relations and inverse binary relations on the meta-classes and the meta-properties corresponding to a transitive closure of the binary relations and the inverse binary relations; business rules on said metamodel for indicating that certain meta-properties have impact consequences, wherein the business rules are selected from the group consisting of arithmetic conversion rules, type restrictions on inherited properties, type restrictions on indirect properties, specifying metadata values as being required, specifying valid ranges for metadata values, specifying metadata values as being unique, lookup tables, naming conventions, and assignments of stewardship responsibilities, and combinations thereof; and an impact analyzer operating on said configurable metamodel for determining which assets of the enterprise IT system are impacted by one or more specified assets, wherein the impact determination of selected from the group consisting of determining which applications and systems will be impacted if a specific server shuts down, determining who needs to be notified if a computer is replaced with a newer model, determining which applications and systems will be impacted if a specific employee is promoted, determining which data sources are fed by data from a specific database, either directly or indirectly, determining which data transformations are impacted if the data type of a specific database column is changed, and combinations thereof.