  Aims: We present an automatised fitting procedure for the IR range of AGB
star spectra. Furthermore we explore the possibilities and boundaries of this
method. Methods: We combine the radiative transfer code DUSTY with the genetic
algorithm PIKAIA in order to improve an existing spectral fit significantly.
Results: In order to test the routine we carried out a performance test by
feeding an artificially generated input spectrum into the program. Indeed the
routine performed as expected, so, as a more realistic test set-up, we tried to
create model fits for ISO spectra of selected AGB stars. Here we were not only
able to improve existing fits, but also to show that a slightly altered dust
composition may give a better fit for some objects. Conclusion: The use of a
genetic algorithm in order to automatise the process of fitting stellar spectra
seems to be very promising. We were able to improve existing fits and further
offer a quantitative method to compare different models with each other.
Nevertheless this method still needs to be studied and tested in more detail.
