VARDA Rule Design and Visualization Tool-Chain

A prototype design tool-chain (VARDA) for the ARD hierarchical rule design method is presented in the paper. It is implemented in the Unix environment using Prolog and Graphviz for design visualization. 1 Rule Design with ARD+ The HeKatE project (hekate.ia.agh.edu.pl) aims at providing design methods and tools that support a rule-based systems design process. Currently HeKatE supports a conceptual design with the ARD+ method (Attribute Relationships Diagrams). The main, so-called logical design, is carried out with the use of the XTT method (eXtended Tabular Trees) [1]. This paper is dedicated to the presentation of VARDA (Visual ARD Rapid Development Alloy), a rapid prototyping environment for the ARD+ method. The main objective of ARD+ is to capture relationships between attributes in terms of Attributive Logic [2]. Attributes denote certain system property. ARD+ captures functional dependencies among these properties. Such dependencies form a directed graph with nodes being properties. There are two kinds of attributes: a conceptual attribute is an attribute describing some general, abstract aspect of the system to be specified and refined; a physical attribute is an attribute describing a well-defined, atomic aspect of the system. There are two transformations allowed during the ARD+ design process. Finalization transforms a simple property described by a conceptual attribute into a property described by one or more conceptual or physical attributes. It introduces a more specific knowledge about the given property. Split transforms a complex property (source property) into a number of properties (resulting properties) and defines functional dependencies among them. Attributes are unique, the same attribute cannot describe more than a single property. The evolution of the hierarchical ARD+ design is captured within the Transformation Process History. The TPH forms a tree that allows for recreation of any stage of the design. ? The paper is supported by the Hekate Project funded from 2007–2009 resources for science as a research project.