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 application modeling within that domain. Most domain analysis approaches suffer from low accessibility and limited expressiveness. In this paper we utilize the application-based domain modelling (ADOM) approach and apply it to the Object-Process Methodology (OPM) modelling language. We do that by extending Object-Process Methodology (OPM) to support domain analysis. We also performed an experiment to verify that the proposed extension improves the model quality compared to quality arrived at without the extension. Our experimental results show that, when presented with a set of requirements, subjects that used OPM with the domain analysis extension arrived at a system model which is ten percents better than the system model arrived at by subjects that used OPM alone in terms of model correctness.