Automating Preference and Change in Workflows

Workflow languages can compose and sequence Web service invocations to achieve meaningful task results. Updating workflows when services and task goals change is difficult, and automating the change at runtime requires workflow goals and service preferences to be stated, organized, and controlled. Changing the preferences should be immediately reflected in executing workflows. While there are many applications that could benefit from this dynamic reconfiguration, managing such preferences can be daunting. We introduce NeWT, a Next-generation Workflow Toolkit that combines workflow editing with utilities for introducing and managing change. NeWT allows the novel input of goal preferences to use workflows that accomplish the same task but in different ways to be interchangeable according to the current goal. It accepts that multiple, competing Web services will be available and should be interchanged as dictated by need. We detail the implementation of these concepts using a crisis management example.