A method for monitoring an installation having first and second energy operating states, and a different energy consumption in the first and second energy operating states, wherein the method comprising changing over the installation by a first switching command from the first into the second energy operating state, determining a first changeover time period between the beginning of the changeover process and the attainment of the second energy operating state, and storing the first changeover time period in a database for changeover time periods which is assigned to the installation, storing state information, determined using the first changeover time period, regarding the installation in a state database assigned to the installation.