Representing Product Designs Using a Description Graph Extension to OWL 2

Product development requires the ability to check design consistency, to verify design properties, and to answer questions about a design's possible implementations. These tasks require inference based on design knowledge. The inference depends on having a representation of the design that is sufficiently precise to capture the design's intended meaning. Description Logics are languages with a formal logical semantics that have been engineered for conceptual modeling. OWL 2 is a W3C standard based on Description Logic. For algorithms that use inference to be guaranteed to produce an answer to a question the design knowledge base must generate a decidable theory. While OWL 2 has a decidable formal semantics it does not provide the expressiveness needed to constrain the possible interpretations of a design to be the intuitively valid physical implementations. A Description Graph Extension to Description Logic can be used to enhance expressiveness and eliminate design models that do not reflect the intended meaning. In a Description Graph extension a product design is represented as a Graph- Extended Knowledge Base (GEKB). A GEKB contains an embedded a description graph, such as a SysML block diagram, which represents the structure of the design. To achieve a decidable theory a product design KB is restricted to represent a Product Line. A Product Line is a top level design with specific variants that refine the top level design. A Product Line KB is decidable and its models have the structure intended for implementations. GEKBs provide a method to integrate SysML into a DL language tailored for product development that has a formal semantics.