Semantic Model Differencing Based on Execution Traces

Managing the evolution of software artifacts is a crucial issue in software engineering. As in the software engineering paradigm model-driven engineering (MDE), the main software artifacts are models, managing the evolution of models constitutes a key concern in MDE. One important technique in this realm is model differencing, which is concerned with identifying differences among different versions of models. While the majority of existing model differencing approaches use a purely syntactic approach, we propose an approach that takes the semantics of models into account. In particular, our approach utilizes the behavioral semantics of the used modeling language to execute the models to be compared and obtain execution traces constituting the models’ semantic interpretation. By comparing the obtained execution traces, semantic differences among the models are identified. Model differencing is concerned with the identification of differences among independently developed or consecutive versions of models. Therewith, it constitutes the basis for performing important change management tasks, such as model merging, model versioning, conflict detection among concurrent changes, and incremental testing. The majority of existing model differencing approaches use a syntactic approach, which applies a fine-grained comparison of two models based on their abstract syntax representation. The result of this comparison is a set of syntactic differences among the considered models, such as model elements existing in only one of the models. Although syntactic differences constitute valuable and efficiently processable information sufficient for several application domains, they are only approximations of the semantic differences among models. As pointed out by Maoz et al. [MRR11], a few syntactic differences among models may induce very different semantics and syntactically different models may still induce the same semantics. Until now, only a few model differencing approaches have been proposed that take the semantics of models into account. Maoz et al. [MRR11] and Fahrenberg et al. [FLW11] propose general procedures for realizing semantic differencing operators requiring the definition of the used modeling language’s semantics as a translation into an adequate semantic domain and the implementation of the semantic model comparison in this semantic domain. However, developing semantic differencing operators in this way constitutes a major challenge, as one has to develop translations of models into a semantic domain, comparison algorithms in this semantic domain, and translations of comparison results back into the originally used modeling languages. To mitigate this challenge, we have developed a generic semantic model differencing framework [LMK14] that can be instantiated to realize semantic differencing operators for