Reusability Metrics in Search-Based Testing of Software Product Lines: An Experimentation

Reusability is one of the most important objectives in software development and especially, in software product line (SPL) engineering, involving analysis, design, implementation, testing, and maintenance activities. Therefore, in software product line testing, as well as other activities, it is crucial that we pay special attention to reusability. In SPL testing, reusability can be defined and measured in different ways. In this paper, we first introduce four different reusability metrics for SPL testing (SPLT); and then, as a first step toward improving reusability in SPLT, we experimentally examine how a search-based software testing (SBST) approach for optimizing an existing SPL domain test suite can affect (improve) two of the proposed reusability metrics. The results of the experimentation on 20 SPL feature models of size 5000 showed a significant improvement in the two selected test reusability metrics, namely, TSRR (test suite reusability regarding test requirements) and TCRR (test case reusability regarding test requirements) in optimized solutions compared with non-optimized solutions.