A low-level process, which was mapped from a high-level graphical notation diagram, is debugged using the high-level graphical notation diagram. To debug the low-level process, a debugging interface allows a user to set and track breakpoints and other debug events from the high-level graphical notation diagram. When a breakpoint or other debug event is encountered during low-level processing, the high-level graphical notation diagram is updated to show the status of the low-level process.