Different kinds of design structure are created and used in engineering design and development processes. Function structures, design grammars and bills of materials are common examples. However, there is a lack of clarity regarding distinctions and similarities between different kinds of structure and systematic ways to articulate them. This paper brings together research on product structuring and shape computation to inform the specification of principles for the definition of design structures. The principles draw together findings reported in the computational geometry and product definition literature with research from a range of companies and industry sectors that encompasses enterprise and process structures. The potential value of the principles to computer-integrated manufacturing and through-life support is demonstrated through application to four case studies.Keywords: engineering design; design informatics; bill of materials; function structure Introduction Engineering design is an important early stage of the innovation processes that deliver new products to markets where societal challenges are addressed and wealth generated. High-quality engineering design information is critical to the effective and efficient manufacture, production and through-life support of such products. The emerging discipline of engineering design informatics brings together ICT (Information and Communications Technology) and engineering design to support the creation of well-founded engineering information support systems. However the current state-of-the-art is characterised by experience-based frameworks and approaches from engineering design coupled with general purpose ICT frameworks (such as SYSML) which provide wideranging functionalities but require substantial effort and scarce expertise to create even demonstrator solutions. These problems can be attributed, in part, to shortcomings in the cognate body of knowledge that underpins the discipline of engineering design which result in slow incremental progress based on a series of ad hoc solutions with few if any high-impact breakthroughs. The importance of the discipline of engineering design informatics is growing for CIM because digital information is becoming a key input to and platform for manufacturing systems. These systems have a direct impact on the effectiveness and efficiency of manufacturing operations and, as a result, deficiencies in the information that drive them are likely to become a limiting factor in system performance. In addition, design information provides new opportunities as a critical underpinning to enable the closing of loops between manufacturing and design, so offering the potential for design to be better informed by manufacturing practices and experiences.The goal of this paper is to contribute requirements for an underlying theoretical framework for the representation and structuring of design and manufacturing information that will address these issues and contribute to the creation of affordable, efficient and effective ways to s...