Taentzer, GabrieleSalay, RickStrüber, DanielChechik, MarshaTichy, MatthiasBodden, EricKuhrmann, MarcoWagner, StefanSteghöfer, Jan-Philipp2019-03-292019-03-292018978-3-88579-673-2https://dl.gi.de/handle/20.500.12116/21133We present our paper from the proceedings of the 2017 edition of the MODELS conference. Software product lines are used to manage the development of highly complex software with many variants. In the literature, various forms of rule-based product line modifications have been considered. However, when considered in isolation, their expressiveness for specifying combined modifications of feature models and domain models is limited. In this paper, we present a formal framework for product line transformations that is able to combine several kinds of product line modifications presented in the literature. Moreover, it defines new forms of product line modifications supporting various forms of product lines and transformation rules. Our formalization of product line transformations is based on category theory, and concentrates on properties of product line relations instead of their single elements. Our framework provides improved expressiveness and flexibility of software product line transformations while abstracting from the considered type of model.ensoftware product linesmodel transformationformal methods for software engineeringText/Conference Paper1617-5468