A method and system for specifying categories of data elements during a service specification phase of a service-oriented architecture (SOA) life cycle defined in a service modeling methodology like Service-Oriented Modeling and Architecture (SOMA). A Unified Modeling Language based SOA modeling tool for SOMA methodology includes a middleware based integration plug-in that categorizes retrieved service-specific data elements as transaction elements, optional controller elements, glue elements, optional extension patterns, extension elements and core Common Information Model entities, and associates the categorized data elements with corresponding operations of the service being modeled. A user interface provided by the plug-in enables input of the data elements into the categories and input of the associations between the categorized data elements and corresponding operations of the service being modeled. Furthermore, the plug-in generates and initiates storing of a service specification based on the categorization of the data elements.