Graph Grammar Based Product Family Modeling

Abstract

Many industries are shifting from mass production to mass customization, which demands quick response to the needs of individual customers with high quality and low costs. The development of product families has received an increasing interest in recent years because, by sharing components across products, a family of products can be derived to cater variety while maintaining the economy of scale. Aiming at the computerization, and eventual automation, of product family design, this paper tackles the formal representation issue surrounding this economically important class of engineering design problem. Breaking free from conventional understanding of product families, which is limited as shared components, the paper defines a product family as a structured system to create variety of products with shared core product technologies. It not only involves the shared base product, but also encompasses customization modules, standard designs, and primary patterns of variety to generate custom designs. The paper introduces graph grammar formalisms to the modeling of such a product family. Based on Programmed Attributed Graph Grammars (PAGG), the graph language is developed to specify the design space of the product family. The process of customizing the base product through manipulating particular modules is modeled by rewriting the starting graph using a series of productions according to the control diagram. Configuration constraints are dealt with by defining application conditions for production rules. Control diagrams are constructed to capture complex relationships among modules and used to control the application sequence of production rules. A case study of power supplies is presented to demonstrate the potential of the graph grammar based modeling approach.