There are strong associations between standard of living, and energy and materialuse in the society. In fact, a higher “consumption” of energy and materials is often regardedas synonymous with human wellbeing. To make this fit in with the ideas of thesustainable society, it is important to assure that the industrial systems are designed inan energy and material efficient way, and to enhance the understanding of which barriersor bottlenecks we must do something about to become even more efficient in the future.The MIND method (Method for analysis of INDustrial energy systems) has been developedto model different types of industrial energy systems. The method can also beused to model and analyse other aspects of industrial systems, not only the energy issues.The system to be analysed with the method is represented as a network of processnodes, and nodes representing auxiliary units, connected by energy and material flows.The MIND method is based on Mixed Integer Linear Programming (MILP), meaning thatrelationships in the system are normally described as linear functions. The potential ofthe MIND method is that it enables a simultaneous representation of the total industrialsystem, a production site, or several aggregated production sites. By focusing on the largersystem, the centre of attention can be drawn from optimisation of the productionprocesses one by one, as in traditional process development. Instead, it is possible tofocus the analysis on the flexibility and the most favourable interactions between differentparts of the system.Examples on industrial systems for material production, which have been modelledusing the MIND method, are pulp and paper production and steelmaking. Both types ofmaterial production involve several processing steps with a high degree of heat and materialmanagement. Another likeness is that both materials can be produced from recycledmaterials and that the recycling rates from the society are among the highest, comparedto other materials. The MIND method has shown grand potentials for analysis ofthese productions system, and also for other systems, such as food manufacturing andchemical industries. It can also be used for analysis of possible synergies betweenneighbouring industries, or between an industry and the nearby society. In this paper themethodology will be described and references will be made to projects where MIND hasbeen used in pulp and paper production and steelmaking.