"Workflow at its simplest is the movement of documents and/or tasks through a work process. More specifically, workflow is the operational aspect of a work procedure: how tasks are structured, who performs them, what their relative order is, how they are synchronized, how information flows to support the tasks and how tasks are being tracked." -- Wikipedia
So workflows offer the possiblity to make the usage of modules more flexible. For example you could apply the submit/approve scheme to every module. Or you could add another step: User submits, lector corrects, editor approves
But workflows don't only organize the cooperation of user groups in a publishing process. They can also start automatic functions like sending a mail when a new user submits an article. Or it could also add the new article as a new thread into a forum.
Axel Guckelsberger experimented with the workflow system that is already included in Pagesetter. In his tutorial "Managing pnCommerce with Pagesetter
" he describes how a item in Pagesetter is paralelly added/edited/deleted in pnCommerce. This makes it possible to manage the products with pagesetter and only use pnCommerce cart and order functions.
Another nice example of how to add a brand new feature to a module by only putting some XML into a workflow file is Markus Gossmer's "save as
feature for Pagesetter. With this you can edit an existing item, edit it and save it as a new publication. Which is very useful if you e.g. have to add several similar events to a calendar.
There is already some documentation on the .8 workflow system
in the Wiki whereas the according API Docs
are still a bit rough.
Managing pnCommerce with Pagesetter
"save as" for Pagesetter
Workflow API docs