When planning and developing new production plants, the focus is no longer only on the required investment costs and the required unit output, but a shift in focus to operating costs, energy consumption and sustainability can be observed. In the case of car body production lines in vehicle manufacturing, there is also a demand for increasing flexibility due to ever shorter product life cycles and smaller product volumes. Concepts for increasing flexibility in car body construction and for more energy-efficient production are already being implemented. In this paper, a new concept is presented that takes both requirements into account and implements them. The impact of the implementation of lightweight engineering and of a new approach, process lightweight engineering, are investigated on a change of operating resources concept. The results of both studies are presented, and the potentials of the results are evaluated and discussed. The results shown that this method enables an increase in flexibility with reduced energy consumption. It is a method to improve the production lines and fulfill the requirements of the future car body shop.