In 8.0.1.x, it is not as easy as in the upcoming LiveCycle ES update 1...which allows you to invoke and see a process execute in Workbench - I digress, you can do use the following in the current released described at:
- Goto
www.adobe.com/go/learn_lc_workbench and see the section Creating Processes > Testing and Troubleshooting Process Versions > Troubleshooting process versions , which describes how to use exception catching and the Variable Logger service to debug a process.
Hope that helps!