A relation-based product model for computer-supported early design assessment

It is widely recognised that there is a need for enhanced computer support during the early stages of product development since most functions of computer-aided-design and manufacturing tools are aimed at the later stages at which time the majority of product cost is already committed. Product models are an essential element in CAD tools and therefore, it is important that product models are available which are suited to use in the early design stages. This paper reports on an aggregate product model schema which can be used throughout the design of a product. The concept of relations between features is used to allow the extension of the model from conceptual to detailed design stages. Feature relations are an integrated representation system for dimensioning, tolerancing and connectivity modelling. This unified approach enhances the development of design assessment tools, in particular the product quality assessment functionality of the CAPABLE system.