Did you know that QGIS can design graphical models, similar to the way Model Builder in ArcGIS works? The following video is taken from my course Learning the FOSS4g Stack: QGIS Desktop.
The capabilities are still a little raw, but you’ll see in this short video that you can indeed create, document, and run a complete GIS model that you simply draw on your screen.
As I mentioned, this video is part of an entire course on QGIS, called Learning the FOSS4g Stack: QGIS Desktop. You can check out the course here. In fact, you can check out all of my courses at www.gisadvisor.com.