The models below were generated automatically to support empirical studies on the performance and scalability of automated techniques for reasoning on feature models. In each generated model, each type of mandatory, optional, inclusive-OR and exclusive-OR feature was added with equal probability. The branching factor (number of children per parent node) of the feature tree varied from 1 to 6. The cross-tree constraints were generated as a single Random 3-CNF formula. More details about these kinds of generated feature models can be found in the section below about our feature model generator tool.