Furthermore, the Thesis covers the development and evaluation of an approach for the know-how and quality assurance during the modular plant layout. The significant effort is put to the representation of the modular structure and its contents with respect to its functionality. Apart from that, a clear structure of the hierarchical process layers and corresponding process plant layers - modules of different complexity - is referred to the existing norms. This includes functional-, plant- and layout-based modularization aspects that characterize appropriate module relationships and enable a holistic module handling during the plant layout. In this context a module-based approach is arranged in such a way that, in addition to the know-how and quality assurance of the developed modules, it also considers and supports other aspects, such as engineering- and equipment-reuse, as well as cost estimation during the plant layout.