The invention relates to a method for normalizing, storing and/or displaying curves describing the adequacy of a kidney substitution treatment during said kidney substitution treatment wherein the kidney substitution treatment is provided by a machine, which has an extracorporeal blood system (31,32) pumping the patient blood at a preset blood flow rate through the blood chamber (30) of a dialyzer, which is divided by a semi-permeable membrane into the blood chamber (30) and a dialyzing fluid chamber (29) and wherein the dialyzing fluid flows at a preset flow rate through the dialyzing fluid system (20,36) of the machine and collects the waste products from the patient after flowing through the dialyzing fluid chamber of the dialyzer and wherein a device (37) able to measure continuously any kidney substitution treatment related waste product to deliver together with the data provided by the kidney substitution treatment machine an adequacy parameter wherein the device is coupled with the dialyzing fluid system of the kidney substitution treatment machine and wherein curves describing the adequacy of the kidney substitution treatment are normalized to make them comparable, and/or stored in an adequate media and/or displayed on the user interface of the machine delivering the kidney substitution treatment and wherein there are available means to calculate parameters quantifying the adequacy differences between treatments.