Modularity intersects technical aspects with the business aspects. This paper analyzes modularity from this intersection point of view. It involves design for modularity as well management of modularity. Methods for supporting modular design are analyzed in relationship with technologies and tools for modular design. The current trend is toward usage and integration of different technologies such as advanced CAD systems, product configurators, agent-based systems and PDM systems. Development of intelligent models and intelligent tools as well as the development of intelligent modular products (i.e. intelligent system: model-tool-product), which can communicate and cooperate, demands the design of more intelligent organizations of modular design. Development of intelligent model-tool-product systems needs the development of holistic and concurrent engineering approaches. These approaches can offer the possibility of the design of intelligent self-sustainable models and intelligent self-sustainable products.