Manufacturing companies face the challenge of understanding and improving complex factory systems in order to stay competitive in a turbulent environment. Interrelated and overlapping life cycles of products and physical factory elements (e.g. machine tools, technical building services, building shell) are challenges to be handled in factory planning and operation. This work discusses both qualitative and quantitative factory life cycle models, analyzing addressed sustainability goals. Due to the lack of quantitative life cycle description models on higher system levels, a concept for aggregating life cycle models from shop floor up to site level is developed. The concept is consequently applied in a case study where cost curves are calculated over the factory's life span and are aggregated to support factory planning and operation.