You can create diagrams using Business Process Modelling Notation (BPMN) with CaseComplete's free-form diagramming and this shape library (template).
Download the template file from the link below and save the file to your computer.
To use the template, create a new diagram (or open an existing diagram). Choose the "open shape library" icon from the shapes library toolbar. Select the template file you downloaded.
Once the library is opened, you can drag and drop BPMN shapes and connectors onto the diagram surface. See the CaseComplete diagramming tutorial for general diagramming tips and procedures.
Useful for "quick" (relative) BPMN-like diagramming. For true BPMN models, should use a tool that's designed for BPMN functionality (e.g. Enterprise Architect).
I'm a big fan of EA from Sparx, I have been using it for ten years, it's a useful 'swiss army' knife for a BA, but it has a steep learning curve and to be honest was NOT designed as a requirements management system - this functionality was added in later releases and it shows to be a bolt on -- to each his own, but Case Complete is more of a requirements tool - not a UML design tool. There are no 'one stop' shop tools - I've looked for a long time :/