Defining relationships among product architecture, product life-cycle modularity, and product life-cycle cost

It is the goal of this research to significantly add to the science of modular product design. Important issues missing at the foundation of modular product research include: Many modularity measure and methods exists but there is no basis to compare them. There is neither a widely adopted measure of a product's modularity nor a widely adopted systematic methodology that helps designers increase the modularity of a product either.; The goal of this research is to better understand the fundamental relationship between product modularity and product cost. It was our hypothesis that redesign results from real products using a correct modular product design procedure would expose relationships between modularity and cost. Using these relationships, better informed product architecture decisions can be made early in the product development process. This work used an analysis of existing modular design research as a starting point.; Seven representative measures were compared based on consistency analysis and sensitivity analysis. Siddique et al.'s measure was selected as the best representative measure with more sensitive to redesign change. The performance of this "best" measure was further verified by redesigning a modularity matrix to test whether the matrix can be redesigned back to its optimal modular state from an initial scrambled state. Two substantial problems emerged---trending towards a non-optimal design and a significant measurement bias introduced by the chosen input scale. By subtracting the averaged relationships external to modules from the averaged relationship within modules, a new measure was created that does not exhibit the trend and bias problems and adheres even more closely to the definition of product modularity. We suggest that this measure be adopted for future applications. (Abstract shortened by UMI.)...