A navigational data model for object modeling technique development environment

Extant tools supporting Object Modeling Technique (OMT) have a serious drawback that they fail to capture a lot of relationships inherently existing among design objects. This drawback may not only disallow designers to freely navigate the relationships but also make it difficult to automatically enforce integrity constraints derived from the relationships. To overcome the drawback, we propose a navigational data model called FONASSE (FOur-dimensional NAvigation Spaceship for Software Engineering). The data model captures four structural relationships among design objects: part of, the other development stage of, the other representation of, and version of. A considerable part of structural semantics the design objects inherently have, can be well captured with the relationships. Since the four relationships are mutually exclusive with each other, de-signers may navigate a set of design objects in a four-dimensional space. Supporting the relationships at system level also entails the automatic enforcement of corresponding integrity constraints. We identified four integrity constraints, each of which is derived from one of the four relationships. In this paper, FONASSE is fully developed as a model suitable to the four-dimensional navigation. As a first step towards such development, a navigation function is defined to formally specify the semantics of queries related with the navigation. The queries, which turn out to be a specification of navigation paths, can be uniformly formulated by the combination of the navigation functions. The integrity constraints corresponding to the relationships are also expressed in terms of the navigation functions. Finally, we provide a scenario to explain the navigational characteristic of our model.