Resource efficiency in companies targets economic and efficient use of materials and energy in production. On the one hand, this aims to contribute towards sustainable development and, on the other hand, efficient use of resources can save costs and improve the competitiveness of a company. This aspect is becoming all the more important in the light of current developments in world market prices for natural resources. In Germany, the use of materials and energy currently accounts for about 46% of the gross value of goods manufactured by companies. It is known from various sources that the average potential for savings here is 10-15%. The material costs alone can be reduced by 2-3% through efficient management. The potentials for saving lie less in the individual technologies applied and more in the interplay within and between the complex production systems. That is why one key challenge facing the industry is to ascertain the hidden costs that are in fact linked with inefficiencies in a company. Analysis methods and approaches are necessary for this, such as for example the material and energy flow analysis.