A Structural Approach to Dynamic Migration in Petri Net Models of Structured Workflows
This addresses workflow evolution issues for process management systems, but it appears incremental as it builds on existing change region concepts.
The paper tackles the problem of overestimated change regions in dynamic workflow migration, which incorrectly identifies migratable instances as non-migratable and causes delays. It analyzes this on Petri net models, developing structural properties for minimal change regions and classifying them into Structural and Perfect Structural Change Regions, with necessary and sufficient conditions identified.
In the context of dynamic evolution of workflow processes, the change region identifies the part of the old process from which migration to the new process is guaranteed to be inconsistent. However, this approach may lead to overestimated regions, incorrectly identifying migratable instances as non-migratable. This overestimation causes delays due to postponement of immediate migration. The paper analyzes this overestimation problem on a class of Petri nets models. Structural properties leading to conditions for minimal change regions and overestimations are developed resulting into classification of change regions into two types of change regions called Structural Change Regions and Perfect Structural Change Regions. Necessary and sufficient conditions for perfect regions are identified. The paper also discusses ways for computing the same in terms of structural properties of the old and the new processes.