The imperfection of the technical processes can be revealed with the h
elp of known methods of thermodynamics. The calculation provides proce
ss-specific irreversibility profiles as the basis for a comparative pr
ocess analysis. Based on this, methods can be found, of how a circuit
with the objective of an efficiency increase can be modified (optimiza
tion of structure). In the following, the GuD-Prozess (gas and steam p
rocess) and the GDT-Prozess (gas-steam-turbine process) (in American w
riting known as STIG-process) are investigated correspondingly and the
causes of a reduced efficiency of the GDT-process are shown.