Requirements-based delta-oriented SPL testing

Variability of modern software systems increases potential sources of errors and demands appropriate quality assurance strategies. In order to reduce the test effort when testing software product lines, incremental model-based testing strategies have been proposed, based on the conceptual ideas of delta modeling. It requires executable system specifications to derive and classify test cases. However, in industrial practice such system models rarely exist, but requirements and test cases are captured in natural language. In order to make delta-oriented testing strategies applicable in this context, we transfer them to the requirements level and show how a delta-oriented classification of requirements and associated test cases reduce test effort in these less formal domains.