Model-based test design of product lines: Raising test design to the product line level

System quality assurance techniques like testing are important for high-quality products and processes. The effort for applying them is usually high, but can be reduced using automation. Automated test design is possible by using models to specify test-relevant aspects and by generating tests on this basis. Testing multiple variants of a system like, e.g., a product line of a German car manufacturer, results in a significant, additional effort. In this paper, we deal with model-based testing of product lines. We combine feature models that are used to describe product lines and models that are used for automated model-based test design. Our main contribution is the definition of a test generation approach on the product line level, i.e., that does not depend on resolving single product variants. Furthermore, we compare our approach to other test generation approaches and evaluate it using our tool chain SPLTestbench for some product line examples.