An Architectural Approach to Support Online Updates of Software Product Lines

Despite the successes of software product lines (SPL), managing the evolution of a SPL remains difficult and error-prone. Our focus of evolution is on the concrete tasks integrators have to perform to update deployed SPL products, in particular products that require runtime updates with minimal interruption. The complexity of updating a deployed SPL product is caused by multiple interdependent concerns, including variability, traceability, versioning, availability, and correctness. Existing approaches typically focus on particular concerns while making abstraction of others, thus offering only partial solutions. An integrated approach that takes into account the different stakeholder concerns is lacking. In this paper, we present an architectural approach for updating SPL products that supports multiple concerns. The approach comprises of two complementary parts: (1) an update viewpoint that defines the conventions for constructing and using architecture views to deal with multiple update concerns, and (2) a supporting framework that provides an extensible infrastructure supporting integrators of a SPL. We evaluated the approach for an industrial SPL for logistic systems providing empirical evidence for its benefits and recommendations.