Over the recent years there is a tendency for using domain-specific languages which enable expressing design solutions in the idiom and level of abstraction appropriate for a specific problem domain. While this approach enables an efficient and accurate design, it suffers from problems of standardization, portability and transformation between the models. This paper addresses a challenge of tailoring the Unified Modeling Language (UML) for domain-specific modeling (DSM). We discuss a possible solution for achieving interoperability between UML and the domain-specific language SaveComp Component Model (SaveCCM) intended for real-time embedded systems, by means of implementing a transformation between UML and SaveCCM models. The challenge of the transformation is to keep all necessary information including the domain specific semantics. The paper presents the strategy for the transformation, its implementation and an analysis. We also address the second challenge, a usability of the domain-specific language (i.e. SaveCCM) in comparison with usability of extended UML and by an experiment analyse its usability in comparison with SaveCCM.