The Center for Circular Economy (CCE) bundles the expertise of all faculties of RWTH Aachen University on sustainable circular economy. Trans- and interdisciplinary methods are developed for the process optimisation of the three main areas of the CCE: sustainable product design during production, business models during product use and material recovery during product recycling. The development of these methods is carried out through the interdisciplinary cooperation of a wide range of institutes, some of which look at different stages of the life cycle or the same stages in different sectors. The different technical backgrounds of the institutes thereby enable the development of a comprehensive understanding of Circular Economy and thus abstraction from the individual application.