Evolving System Families in Space and Time

Managing the evolution of system families in space and time, i.e., system variants and their revisions is still an open challenge. The software product line (SPL) approach can support the management of product variants in space by reusing a common set of features. However, feature changes over time are often necessary due to adaptations and/or bug fixes, leading to different product versions. Such changes are commonly tracked in version control systems (VCSs). However, VCSs only deal with the change history of source code, and, even though their branching mechanisms allow to develop features in isolation, VCS does not allow propagating changes across variants. Variation control systems have been developed to support more fine-grained management of variants and to allow tracking of changes at the level of files or features. However, these systems are also limited regarding the types and granularity of artifacts. Also, they are cognitively very demanding with increasing numbers of revisions and variants. Furthermore, propagating specific changes over variants of a system is still a complex task that also depends on the variability-aware change impacts. Based on these existing limitations, the goal of this doctoral work is to investigate and define a flexible and unified approach to allow an easy and scalable evolution of SPLs in space and time. The expected contributions will aid the management of SPL products and support engineers to reason about the potential impact of changes during SPL evolution. To evaluate the approach, we plan to conduct case studies with real-world SPLs.