Abstract: A system, engine, user interface, and methods are described for automating workflow modeling. In one implementation, definitions of objects in a hierarchical model for testing a workflow in a user interface are created, as well as test data to be used in a runtime test of the model. The definitions and the test data can be stored and then the definitions can be retrieved from storage as needed to generate multiple copies of objects for automating construction of the model or construction of a different model. A human operator can arrange visual representations of the objects into a given order on the user interface, for example, by dragging and dropping them, thereby creating the workflow to be tested without writing new code or defining new test data.