DSM-Based Product Representation for Design Process Modularity

An appropriate modularity representation is of critical importance in modular design. Without an appropriate representation, modular design cannot realize its benefits. In this paper, a representation for DSM-based modular product design is developed that facilitates product modularization with respect to the design process. The representation is based upon previous work presented in this venue that details representations for the assembly and manufacturing processes (Lai and Gershenson, 2007a; Lai and Gershenson, 2007b). The representation for the design process includes a design process similarity matrix and a design process dependency matrix. The definition of design process similarity uses information available in early stage design and is based on the similarity of the design tools and resources required for later stage design. Design process similarity within a module leads to increased design efficiency from the sharing of functional and geometric analyses and possibly the savings of not needing to “un-immerse” from a particular design task to “re-immerse” in the design of the next component. The definition of design process dependency is based on the connectivity caused by components’ design process attributes with the goal of fewer design interactions between different modules. With zero dependencies between modules, we hope to contain the cascade of design changes within each module, and prevent the need to redesign other modules. In this paper, we first present which design process elements we should consider for defining design process similarity and dependency, and then construct respective similarity and dependency factors tables. These tables include similarity and dependency factors, which, along with their values, are important in determining a product’s modular architecture at the early stages of design. Finally, a computer mouse is used to illustrate how to apply these factors tables to generate the similarity and dependency matrices that represent product modularity for the product design process. Using these representations as input to the DSM-based modular design methods, we can achieve a design with a modular architecture that improves design efficiency in the later stages of design. In the future, we hope to extend and generalize the process for developing product modularity representations so that it is applicable across all life-cycle processes.