The turbulent transition in the automotive industry towards electric vehicles is highly challenging, both in product development and in production. Conventional, linear assembly lines struggle to meet the flexibility requirements imposed by this market development. Thispaper presents the first mixed-integer programming (MIP) model which is tailor-made for the scheduling of modular body-in-white (BIW)production systems. The main novelty of the presented approach lies in using precedence graphs for modelling the joining steps of the BIW production and allowing for different capabilities at each workstation of the production system. Thus, the presented approach captures the characteristics of BIW production systems in more detail than comparable models available in the literature. The application of the presented approach to an exemplary production scenario with five jobs and 22 operations underlines the strengths of the proposed model but also indicates potential for future improvements.