At present, energy and energy efficiency (EE) related topics are becoming increasingly important due to a growing energy demand and decreasing resource availability. Especially in relation to industrial activities and development, EE measures are arousing interest among decision-makers. Given this background, tools such as energy management systems (EnMS), frequent energy audits and international certifications can contribute to the achievement of continuous energy savings and improve an organization’s overall energy performance. In this context, the following study seeks the elaboration of the planning phase of an EnMS according to the international standard ISO 50001 for the Robert Bosch Automotive Systems plant in San Luis Potosi, Mexico (Bosch SLP). In order to do this, different activities were performed such as interviews with management directives and operational staff members, revision and documentation of already existing energy data as well as the acquisition of new energy data through multi-channel power meter measurements. Some aspects were solely performed on process level while others were established on plant level. According to the objectives proposed in the study the first part focuses on all important concepts related to energy management. Models such as the Plan-Do-Check-Act (PDCA) cycle related to ISO 50001 are presented. Additionally an overview of the Mexican as well as the European Union’s legal frameworks regarding energy audits and EnMS is given. Throughout the thesis, general guidelines for the implementation of an EnMS are described, displaying the planning phase of the PDCA cycle. After presenting the Robert Bosch GmbH as a whole and the Bosch SLP plant in greater detail, the guidelines proposed by the ISO 50001 norm are applied to the study case. In this context, energy policies for Bosch SLP are elaborated and a potential distribution of responsibilities is assigned to the different department managements. Subsequently a detailed energy audit has been completed on process level and data was used to identify opportunity areas and establish an energy baseline, energy management objectives and targets. Already existing energy data from utility bills was reorganized and analyzed in order to realize an energy review on plant level. As a final step of the planning phase an action plan was proposed, however, solely on plant level, since the overall goal for the future should be to duplicate the detailed energy audit throughout the plant. As part of the action plan, a variety of recommendations regarding suitable energy savings measures and activities, needed for the implementation of an EnMS, were suggested.