MIRAGGIO: a System for the Dynamic Management of Product Data and Design Models

An important aspect in developing “intelligent” CAD systems is related to methodologies which are reliable both in handling the relevant information and in modelling the design processes themselves. The intrinsically dynamic nature of these last makes particularly difficult choosing the most suitable methodology to use. This paper describes a prototype Design System, which is capable of generating and dynamically modifying models of design processes and product data that can be considered as Engineering Knowledge Data Bases. The system, implemented in LPA-Prolog++, is based on a hybrid approach that enforces both the Object-Oriented and the Frame paradigms. Frames are mainly devoted to the implementation of the computational model required by the components involved in the design process, while classes are used to assure the inheritance of properties when objects are instantiated or specialized. Information in the Knowledge Data Base is structured using two types of frames: dataFrames, that support the static computational model of the low level components; and linkFrames, that allow for the collection of the low level components into more complex ones without restraining the activation sequence of the pointed frames. In addition, the management of history slots was added to the system in order to associate to the data and process models, at an atomic level, all information related to the rationale of the choices made. The functionality of the system is presented by means of relevant test cases.