Managing Evolving Workflow Specifications

Dynamic evolution of workflow models due to process (re)engineering activities and dynamic changing situations of the real process is one of the most important challenges in workflow management. The authors present an approach for the management of evolving workflow specifications which copes with the evolution of a workflow schema and the dynamic modification of workflow instances. The approach is based on the integrated modeling of workflow schema and instance elements, the separated definition of 'what to do' and 'how to do' in the workflow schema, late binding of workflows at run-time, and the versioning of the workflow schema. On this basis, they support lazy, eager, and selective propagation as well as local customization of instances and their upward propagation. Furthermore, they address the problem of managing consistent configurations of the versioned entities of a workflow schema. In their workflow-specific versioning approach, the consistency of the workflow configuration is guaranteed and hence the version mechanism is transparent to the user.