The use of integrated business software can be instrumental in reducing the difficulties occurring when various information systems have to be integrated. As a downside of this and due to the fact that these systems are designed to be used in all sorts of enterprises, the internal complexity of these systems increases exponentially. Software product lines on the one hand promise remedy by the conscious use of variability, on the other hand create new demands on quality assurance. The article on hand provides a theoretical framework for evaluating approaches to software testing, regarding their use in the development of software product lines. It turns out that only a practice-oriented approach emphasizing the buyer’s view will be successful in the end.