AbstractIn the domain of embedded software systems the increasing complexity of the functionality as well as the increase in variations caused by product lines requires a modular design process, separating function-based and component-based design. As a consequence, functional integration becomes a central task in the development process, to avoid unforeseen interaction. While currently functional integration often is delayed to module integration, leading to a late detection of interactions, here we suggest a methodical approach to the early integration of functions to construct a logical component-oriented architecture.