Within the project "Exergy and Economy", possible future production processes are defined and investigated for selected energy-intensive industries (steel, glass, cement and paper industries as well as parts of the chemical industry (olefins and ammonia)), which lead to the most complete decarbonisation possible of the industry sectors. For a comparative analysis, both the production processes currently used in Germany and the defined future processes will be examined. An indicator-based approach is used for the holistic evaluation of the individual production processes. In addition to energetic, economic and ecological indicators, exergetic indicators are analysed and evaluated. In addition, potentials for industrial symbioses through cross-company use of by-products are investigated for the defined future production processes. A model-based approach based on the exergetic indicators is used for this purpose, which also takes into account the costs of transporting the by-products. Finally, recommendations for an efficient restructuring of existing production processes and locations are derived based on the findings of the study.