AspectOCL: Extending OCL for Crosscutting Constraints

Constraints play an important role in Model Driven Software Engineering. Industrial systems commonly exhibit crosscutting behaviors in design artifacts. While modeling of crosscutting behaviors has been addressed in literature, the modeling of crosscutting constraints remains a problem. Presence of crosscutting constraints makes it difficult to maintain constraints defined on the models of large-scale industrial systems. Multiple elements in a model may share common crosscutting constraints with minor variation. Aspect orientation is well-established approach to model crosscutting behavior. Current OCL specification does not support writing crosscutting constraints separately as aspects. In this paper, we propose an extension of OCL language that brings benefits of aspect orientation to OCL constraints. In our language, crosscutting constraints are specified as aspects, which can be woven in OCL constraints. We demonstrate our proposed language through application on a published open source case study. Results show that specifying crosscutting constraints as aspects can reduce the number of constraints to be specified.