A Typed Approach to User Interaction Modelling

In this chapter, we propose a typed approach to business process specification that supports the integration of workflow definition and dialogue programming and is also open to business process modelling. The resulting key artefact is called workflow chart and still models the control flow of business processes but puts more emphasis on user interaction modelling. Workflow charts are specified as tripartite directed graphs and describe an alternative sequence of typed nodes for showing information and providing forms for user input. Thus, they represent the most detailed level in a hierarchy of business processes and are executable in the sense that they can be interpreted by a workflow management system using a worklist client. A formalisation of workflow charts using Abstract State Machines (ASMs) provides a precise operational semantics. The concept of workflow charts contributes to a more flexible process technology, which is demonstrated by implementing a substantial workflow of a social insurance company.