Interoperability of software product line variants

Software Product Lines are an established mechanism to describe multiple variants of one software product. Current approaches however, do not offer a mechanism to support the use of multiple variants from one product line in the same application. We experienced the need for such a mechanism in an industry project with German Railways where we do not merely model a highly variable system, but a system with highly variable subsystems. We present the design challenges that arise when software product lines have to support the use of multiple variants in the same application, in particular: How to reference multiple variants, how to manage multiple variants to avoid name clashes, and how to keep multiple variants interoperable © 2018 Association for Computing Machinery.