  Variability models (e.g., feature models) are a common way for the
representation of variabilities and commonalities of software artifacts. Such
models can be translated to a logical representation and thus allow different
operations for quality assurance and other types of model property analysis.
Specifically, complex and often large-scale feature models can become faulty,
i.e., do not represent the expected variability properties of the underlying
software artifact. In this paper, we introduce DirectDebug which is a direct
diagnosis approach to the automated testing and debugging of variability
models. The algorithm helps software engineers by supporting an automated
identification of faulty constraints responsible for an unintended behavior of
a variability model. This approach can significantly decrease development and
maintenance efforts for such models.
