Adding variants on-the-fly: Modeling meta-variability in dynamic software product lines

Dynamic software product lines (DSPL) are software product lines (SPL) that support runtime variability. Runtime variability is typically interpreted as binding variation points at runtime. We emphasize meta-variability as an important dimension of runtime variability in DSPL. Whereas dynamic binding considers the runtime (de)activation of variants within the scope of a given variability model, meta-variability considers runtime changes to the variability model itself. Meta-variability is essential to support longlived software products that are subject to evolution. In this paper, we consider meta-variability in an industrial DSPL that is developed in a joint project with Egemin N.V., a leading company that provides full life cycle support for automated transportation systems (ATS). The contribution of this paper is threefold. First, we introduce a way to model meta-variability in DSPL in an explicit manner. Second, we put forward a meta-variability meta model that extends the variability meta model with concepts that explicitly support meta-variability. Third, we capture and apply metavariability in an industrial DSPL for automated transportation systems.