If a diagram according to the BPMN standard is not sufficient for your purposes, you can extend the process diagrams almost unlimitedly.
For example, set up additional swimlanes for e.g. IT systems and display additional documents or risks. You can easily adapt the colors and shapes of the process shapes to your needs.
If required, you can switch the display of the swimlanes between horizontal and vertical. And if you wish, you can use the property visualization to display all information directly on the shape.