Due to the knowledge that the use of all resources is limited, the demand for products and processes which are manufactured respectively operated with low resource and energy consumption is steadily increasing within the last years. This induces the need of systems which are based on a sustainable approach.
The consideration of material as well as energy flows is important since material flows are usually also potential energy flows (e.g. thermal potential of a wastewater stream, the energy content of fuels).
In order to implement measures to increase efficiency or save resources, it is particularly important that a well defined environment with clear system boundaries is defined at the beginning of the work. The system boundaries can be factories, municipalities or also intermediate stages (e.g. industrial zone within a municipality etc.).
