Abstract: A method is provided for determining a characteristic quantity, in particular, the quality and/or performance, of IT systems at the application level, in particular, during operation, wherein at least one application (21, 21?) is started on at least one computer (5) of the system and wherein a time (?t) between the starting of the application (21, 21?) and reaching a certain application state, like its actual availability to a user, is calculated and evaluated for determining the characteristic quantity.