Modeling Product-Line Legacy Assets Using Multi-Level Theory

The use of non-systematic reuse techniques in Systems Engineering (SE) leads to the creation of legacy products comprised of legacy assets like software, hardware, and mechanical parts coupled with associated traceability links to requirements, testing artifacts, architectural fragments etc. The sheer number of different legacy assets and different technologies used to engineer such legacy products makes reverse engineering of PLs in this context a daunting task. One of the prerequisites for reverse engineering of PLs is to create a family model that captures implementation aspects of all the legacy products. In this paper, we evaluate the applicability of a modeling paradigm called Multi-Level Modeling, which is based on the class instance relation, for the creation of a family model that captures all the implementation concerns in an SE PL. More specifically, we evaluate an approach called Multi-Level conceptual Theory (MLT) for capturing different legacy assets, their mutual relations and related variability information. Moreover, we map PL concepts like variants, presence conditions and product configurations to MLT concepts and provide formal interpretation of their semantics in the MLT framework. The illustrative example used throughout the paper comes from a real case from the automotive domain.