Evolutionary Design through Reflective Petri Nets : an Application to Workflow

The design of dynamic workflows needs adequate model ing/specification formalisms and tools to soundly handle possible changes during workflow operation. A common approach is to pollute workflow design with details that do not regard the current behavior, but rather evolution. That hampers analysis, reuse and maintenance in general. We propose and discuss the adoption of a recent Petri net based reflective model as a support to dynamic workflow design. Keeping separated functional aspects from evolu tion, results in a dynamic workflow model merging flexibil ity and ability of formally verifying basic workflow prop erties. A structural on-the-fly characterization of sound dy namic workflows is adopted. An application is presented to a localized problem: how to determine what tasks should be redone and which ones do not when transferring a work flow instance from an old to a new template.