1. A method for implementing information service level inheritance in a network management system, comprising: defining a Web Services Description Language (WSDL) file for an inheriting Integration Reference Point (IRP), including base management operations of a base IRP in the WSDL file for the inheriting IRP during the defining action to establish an Information Service (IS) level inheritance between the inheriting IRP and the base IRP; implementing conversion between a base management operation message and a SOAP format message according to the IS level inheritance.