Abstract

In consequence of changing requirements and technological progress, modeling languages are subject to change. When their metamodels are adapted to reflect those changes, existing models might become invalid. Manually migrating the models to the adapted metamodel is tedious. To substantially reduce effort, a number of approaches have been proposed to fully automate model migration. However, the evolution of modeling languages occasionally leads to metamodel changes for which the migration of models inherently cannot be fully automated. In these cases, the migration of models requires information which is not available in the model. If such changes are ignored or circumvented, they may lead to language erosion. In this paper, we formally characterize metamodel adaptations in terms of the effort needed for model migration. We focus on the problem of metamodel changes that prevent the automatic migration of models. We outline different possibilities to systematically cope with these kinds of metamodel changes.