Hi Vinny,
for BPMN modelling take a look at our simple tool ProcessPad www.processmaster.com (download the free trail) we have a converter to BPEL and UML etc in the works so when you map a process not only will you get instant documentation, you can convert into whatever format you need depending on your audience. No need for hefty BPMN training to get anyone up and running using our simple text entry interface.
hope this helps
Paul
http://www.agilemodeling.com/artifacts/sequenceDiagram.htm
Why wouldn't figure 4 in the link above be modeled as an activity diagram? Why wouldn't it be modeled with BPMN? Reading the step-by-step procedure does describe a business process, correct?
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