Tab-Trees: A CASE Tool for the Design of Extended Tabular Systems

Tabular Systems constitute a particular form of rule-based systems. They follow the pattern of Relational Databases and Attributive Decision Tables. In Extended Tabular Systems non-atomic values of attributes are allowed. In order to assure safe, reliable and efficient performance of such systems, analysis and verification of selected qualitative properties such as completeness, consistency and determinism should be carried out. However, verification of them after the design of a system is both costly and late. In this paper another solution is proposed. A graphical CASE-like tool supporting the design of Extended Tabular Systems and providing verification possibilities is presented. The tool uses a new rule specification paradigm: the so-called tab-trees, covering the advantages of Attributive Decision Tables and Decision Trees. In the system the verification stage is moved into the design process. The background theory and the idea of tab-trees are outlined and presentation of a practical tool, the Osiris System, is carried out.