Langer, PhilipMayerhofer, TanjaWimmer, ManuelKappel, GertiFill, Hans-GeorgKaragiannis, DimitrisReimer, Ulrich2019-03-192019-03-192014978-388579-619-0https://dl.gi.de/handle/20.500.12116/20946While UML is recognized as the de-facto standard in modeling software systems, it is at the same time often criticized for being too large and complex. To be able to evolve UML to overcome this criticism, evidence is needed about which parts of UML are actually used. In this respect, a few studies exist that investigate which diagram types of UML are commonly used. However, to the best of our knowledge, in none of these studies, evidence is provided about which modeling concepts of UML are used. Thus, we quantitatively analyze UML models to determine on a fine granularity level the usage frequency of the modeling concepts provided by UML. In this paper, we present initial results of our analysis of 121 open UML models and compare our findings with the results reported in related studies about the usage of UML.enText/Conference Paper1617-5468