Producing companies face enormous challenges due to increasing customer expectations, global competition and sustainability considerations. In recent years, the concept of the digital twin (DT) has found rising attention, because this concept has the potential to enable, amongst others, superior monitoring, process control, diagnosis, traceability and quality control. Additionally, the concept of a DT may intensify the integration of product development, production planning and production, because it is sensible to initiate the creation of the digital twin already in product development and the potential of this concept can only be fully realized if all phases of the system lifecycle are considered. Extensive research has already covered the application of DTs during production operation, but concerning the application in the product design stage many questions remain. The research described in this paper is focused on the question how design automation concepts can contribute to an automated creation of a DT. The paper explains a novel concept for realizing a digital twin. The novel concept is employing an engineering framework based on graph-based design languages. It is applied to an automotive body-in-white assembly system and aims at supporting virtual commissioning. The digital twin includes geometric and kinetic models and simulations and its creation already starts in product development.