In many industrial sectors, modularization of products and services is considered as an important contribution to increased efficiency and competitiveness. Research has developed many modularization approaches, however, there is a gap between industrial practice in modularization and state-of-research in this field, which partly is due to shortcomings in "measuring"the value and state of modularization. This papers contribution is an analysis of industrial real-world cases to contrast practice and research, and a compilation of metrics in the context of modular product design from research.