UML is an industrial standard for object-oriented software specification which offers a notation for class modeling during object oriented software development. Since the UML class diagram is a so-called “bridge” between software specification at the user side and software realization at the developer side, it requires strong guidelines for identification of class objects from the problem domain and notational conventions for modeling of the class diagram for its further usage in system coding. This paper presents a discussion on problematic stages and possible element transformations into software components. Several conclusions are drawn on potential usage of the class diagram in industry