Variability Modelling for Model-Driven Development of Software Product Lines

Model-driven development of software-intensive systems aims at designing systems by stepwise model refinement. In order to create software product lines by model-driven development, product variability has to be represented on every modelling level and preserved under model refinement. In this paper, we propose ∆-modelling as an generally applicable variability modelling concept that is orthogonal to model refinement. Products on each modelling level are represented by a core model and a set of ∆models specifying changes to the core to incorporate product features. Core and ∆-models can be refined independently to obtain a more detailed model of the product line. Based on a formalization of ∆-modelling, we establish conditions that model refinement and model configuration commute resulting in an incremental model-driven development process. Keywords-Software Product Lines; Variability Modelling; Model-driven Development; Model Refinement