- Domain engineering can simplify the development of software systems in specific domains. During domain analysis, the first step of domain engineering, the domain is modeled at an abstract level, providing guidelines for modeling applications within that domain. Drawbacks of existing domain analysis approaches include poor guidelines for domain-specific application modeling, insufficient validations capability, and limited usability. In this paper we apply the Application-based Domain Modeling (ADOM) to the Object-Process Methodology (OPM). This application requires the extension of OPM with a classification mechanism. Showing that the ADOM-OPM approach overcomes limitations of existing approaches, we further verify experimentally that the level of correctness of an ADOM extended OPM model is higher than that achieved without the extension. Finally, we ensure that the proposed extension does not degrade the generic vanilla form of OPM.