The primary aim of work package 4 is the development of methods supporting the concept of “Energy Efficiency 2.0”. This is a term coined for an approach which goes beyond the current effort to energy efficiency: introduction of technically efficient equipment, reduction of energy waste and mitigation of environmental pollution according to legislative requirements. “Energy Efficiency 2.0” is meant for companies which take a proactive approach in their management towards ecology and sustainability in general. A special concern in the matter is the integration of Renewable Energy Sources (RES) immediately in the production environment of manufacturing companies. For this purpose, a Resource Networks Methodology (RNM) is developed which is aimed to provide an approach which integrates all the different resources (as in requirements for a production operation) into factory planning and control methods. This deliverable details the theoretical background for the RNM and details the exact need for action as well as the requirements for development of the methodology. It discusses the motivation behind the push towards “Energy Efficiency 2.0” from a point of view of the European legislative, European standardisation bodies and the European markets. As RES and energy storages will be a major enabler or even requirement of the RNM, the available technologies and there characteristics are discussed. Furthermore, the state of the art on smart grids and micro grids is presented to give some background on other approaches which are being researched. The deliverable further summarises the state of the art in both science and practice on energy efficiency in production as one of the aspects to be integrated in the RNM. As flexibilities and volatilities are a prime concern of the RNM, a review of these in production systems has been made and is complemented with an overview of other projects considering the issue in relation with the integration of RES. Lastly, the need for action and the requirements for the further developments in Tasks 4.2 and 4.3 of the REEMAIN project are introduced. One example for such requirements is the placement of the RNM in the production system planning process (see Figure 1)