Data Flow and Human Tasks in Business Process Models

In contrast with the traditional view that represents business processes as flow charts of tasks, the artifact-centric one stresses the importance of the data flow, as the main responsible for the activation of the tasks. This viewpoint leads to reconsider the interactions between the process and its tasks as well as the execution mode of the tasks. The greatest benefits concern human tasks; they should no longer be considered only as services implemented by people but they may enable their performers to make choices. Two kinds of human choices are considered in this paper: the choice of the inputs to be acted on, and the choice of the course of action to be taken. The execution mode of human tasks is also examined and three categories are illustrated: performer-driven tasks, process-driven tasks and macro tasks. These categories come with a number of patterns, which are exemplified in this paper.