Abstract: A method for optimizing the energy management and reducing the greenhouse gas emissions of a complex aeronautical assembly comprising at least one aircraft and an auxiliary power unit (APU). The method analyzing, in a centralized manner outside the aeronautical assembly, data from the aeronautical assembly to compare at least one state of a parameter of the assembly with a predetermined optimal state of the parameter. The data measured by sensors of the aeronautical assembly are collected. The collected data is transmitted to a digital processing and analysis platform. The data is processed by the platform implementing machine learning algorithms. Information relating to the processed data is displayed on a dashboard accessible via different terminals. A real-time alert is generated in the case of detection of an anomaly in the aeronautical assembly.