Abstract: Design rationale (DR) is crucial information in product design analysis, design reuse, design reasoning and design evaluation. Based on the foundation of issue-based information system (IBIS) model，a new ontology-based semantic representation model for DR information—ISAA model is proposed. ISAA model introduces the ontology-based semantic representation mode to the DR representation and expands the concept elements of IBIS. The ontology definitions of issue concept, solution concept, and argument concept as well as other four concepts of DR are given. The semantic relationships between concept elements are also defined. The axioms and rules which are used to restrict and constraint the existed relations and create new relations by reasoning are analyzed and defined. The defined rules also rich the semantic relations of DR representation defined by web ontology language (OWL). The ISAA model represents the directed graph of IBIS to resource description framework (RDF) graph and serializes to RDF / XML document which lays foundation for retrieving and reasoning semantic information of DR. A semantic annotation interface integrating with the product CAD model is developed, which captures and abstracts the discrete information of DR thinking to conceptual information of ISAA model. An example of representing DR of spring charge for high-voltage circuit breaker is taken to embody and validate the ISAA model.

Key words: Design rationale, Design semantics, Ontology, Representation model