SDL is recommended by the CCITT as the standard language used both to specify the required behavior of a system and to describe the actual behavior of a system. Many tools have been developed to support SDL, but because of the differences in the internal representation among them, it is hard to integrate these tools together to provide an integrated SDL environment.
In this thesis, we propose a SDL data model for tools supporting SDL which not only provides a consistent internal representation of SDL, but also meets the functional requirements of it and its environment. The data model is based on object-oriented concept. We also implement a prototype system for supporting the data model as a front-end system of Wisconsin Storage System (WiSS) running under the UNIX system.