User interface engineering for software product lines: the dilemma between automation and usability

Software Product Lines (SPL) are systematic approach to develop families of similar software products by explicating their commonalities and variability, e.g., in a feature model. Using techniques from model-driven development, it is then possible to automatically derive a concrete product from a given configuration (i.e., selection of features). However, this is problematic for interactive applications with complex user interfaces (UIs) as automatically derived UIs often provide limited usability. Thus, in practice, the UI is mostly created manually for each product, which results in major drawbacks concerning efficiency and maintenance, e.g., when applying changes that affect the whole product family. This paper investigates these problems based on real-world examples and analyses the development of product families from a UI perspective. To address the underlying challenges, we propose the use of abstract UI models, as used in HCI, to bridge the gap between automated, traceable product derivation and customized, high quality user interfaces. We demonstrate the feasibility of the approach by a concrete example implementation for the suggested model-driven development process.