Abstract: The invention refers to a method 200 for assisting an energy consumption optimization of an industrial plant site. Data is received 210 from sensors, wherein the data comprises a tag identifying a sensor and measurements performed by the sensor. A graph database model is received 220 associated with the industrial plant site. The graph database plant model is formed by a graph database comprising operation nodes related to operation assets, transport nodes related to a mass transport and sensor nodes related to sensors. The edges of the graph database are indicative of the relation between the different nodes. A waste heat and/or heat sink potential is determined 230 for a part of the industrial plant site based on the graph database plant model and the data of the sensors. Control signals are provided 240 based on the waste heat and/or heat sink potential.