Please see also http://www.workflowpatterns.com/. Historically, BPMN by itself was regarded difficult to automate. BPEL as a workflow language (Oracle SOA, Microsoft BizTalk server) can be interpreted easily by machine, but it is not so easy to learn by the people who have to model the process. There were some effors to make an automatic translation from BPMN to BPEL but it didn't succeed - it was a true challenge, and the platforms that I mentioned in previous email were already coming to the stage, so this idea went downhill. YAWL is another workflow language attempt, however it is not widely accepted, in my opinion from similar reasons as for BPEL. As I said, a possible direction is to go for BPMN. It can be based on Workflow Patterns "behind the scenes". Here's an example of this approach in Python https://github.com/knipknap/SpiffWorkflow. However, the platforms that I mentioned have "... an embeddable, lightweight process engine in Java, supporting native BPMN 2.0 execution ..." (https://en.wikipedia.org/wiki/JBPM) and similar, so a direct support for BPMN 2.0 shouldn't be too difficult after all. One of the advantages to build an engine in Pharo around BPMN is that it would be directly usable by a large community that works on processes digitalization. They understand the processes and the notation. Best wishes, Tomaz -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html