On the structure of problem variability: From feature diagrams to problem frames

Requirements for product families are expressed in terms of commonality and variability. This distinction allows early identification of an appropriate software architecture and opportunities for software reuse. Feature diagrams provide intuitive notations and techniques for representing requirements in product line development. In this paper, we observe that feature diagrams tend to obfuscate three important descriptions: requirements, domain properties and specifications. As a result, feature diagrams do not adequately capture the problem structures that underlie variability, and inform the solution structures of their complexity. With its emphasis on separation of the three descriptions, the problem frames approach provides a conceptual framework for a more detailed analysis of variability and its structure. With illustrations from an example, we demonstrate how problem frames analysis of variability can augment feature diagrams

A Text-based Approach to Feature Modelling: Syntax and Semantics of TVL

International audienceIn the scientific community, feature models are the de-facto standard for representing variability in software product line engineering. This is different from industrial settings where they appear to be used much less frequently. We and other authors found that in a number of cases, they lack concision, naturalness and expressiveness. This is confirmed by industrial experience. When modelling variability, an efficient tool for making models intuitive and concise are feature attributes. Yet, the semantics of feature models with attributes is not well understood and most existing notations do not support them at all. Furthermore, the graphical nature of feature models' syntax also appears to be a barrier to industrial adoption, both psychological and rational. Existing tool support for graphical feature models is lacking or inadequate, and inferior in many regards to tool support for text-based formats. To overcome these shortcomings, we designed TVL, a text-based feature modelling language. In terms of expressiveness, TVL subsumes most existing dialects. The main goal of designing TVL was to provide engineers with a human-readable language with a rich syntax to make modelling easy and models natural, but also with a formal semantics to avoid ambiguity and allow powerful automation