Adjustment strategies for non-compliant process instances

Enabling changes at both process type and process instance level is an essential requirement for any adaptive process-aware information system (PAIS). Particularly, it should be possible to migrate a (long-)running process instance to a new type schema version, even if this instance has been individually modified before. Further instance migration must not violate soundness; i.e., structural and behavorial consistency need to be preserved. Compliance has been introduced as basic notion to ensure that instances, whose state has progressed too far, are prohibited from being migrated. However, this also excludes them from further process optimizations, which is not tolerable in many practical settings. This paper introduces a number of strategies for coping with non-compliant instances in the context of process change such that they can benefit from future process type changes on the one hand, but do not run into soundness problems on the other hand. We show, for example, how to automatically adjust process type changes at instance level to enable the migration of a higher number of instances. The different strategies are compared and discussed along existing approaches. Altogether, adequate treatment of non-compliant process instances contributes to full process lifecycle support in adaptive PAIS