The Builder allows to test all operations of a service at runtime in a model based fashion. It is not only possible to test and trace synchronous calls to a service but also asynchronous threads, for instance such of time triggered events or asynchronous tasks of a persistent state engine.
The Interactive xUML Debugger allows to set breakpoints in the activity diagrams of the UML models. Actions of an activity diagram within MagicDraw can be stepped directly into and user can examine the executed action script and the runtime values of all objects.