Formalization of MOF-Based Metamodels

Formal and semiformal techniques can play complementary roles in MDA-based software development processes. We consider it beneficial for both semiformal and formal specification techniques. On the one hand, semiformal techniques lack a precise semantics; however, they have the ability to visualize language constructions, allowing a great difference in the productivity of the specification process, especially when the graphical view is supported by means of good tools. On the other hand, formal specification allows us to produce a precise and analyzable software specification and clarifies the intended meaning of metamodels, helps to validate model transformations, and provides reference for implementations; however, they require familiarity with formal notations that most designers and implementers do not currently have and the learning curve for the application of these techniques requires considerable time. A combination of metamodeling and formal specification techniques can help us to address MDAbased processes such as reverse engineering, forward engineering and round-trip engineering. In light of this, we propose to use the algebraic metamodeling language, called NEREUS which can be viewed as an intermediate notation. NEREUS can be integrated with different formal languages and object-oriented languages. It is particularly suited for specifying metamodels based on the concepts of entity, relation and system. Most of the MOF metamodel concepts can be mapped directly to NEREUS. In terms of NEREUS we will explain a reusable infrastructure for more efficient development of evolution system techniques and high quality of the results. In the following sections we summarize the main specification languages linked to object-orientation approaches such as UML and MDA and, motivate the use of NEREUS as a metamodeling language.