Process Modeling: using Visio to create Petri Nets

Although the case has been made not to use Visio as a process modeling tool...

http://process-cafe.blogspot.com/2008/03/visio-devils-tool.html

... I created a Visio stencil for creating Petri Nets anyway.

Download the stencil to create your own:

Visio Stencil - Simple Petri Net Routing.vss

Example file shown above:

Visio Stencil - Simple Petri Net Routing.vsd

Likely it will create essential parts of Petri Nets but not exactly do what you want. To edit it use the Visio ShapeSheet properties, see here.

http://msdn.microsoft.com/en-us/library/aa200977%28v=office.10%29.aspx

Any feedback is welcome in the comments!