Hello everyone, I have two question, the first one is what does the External System exactly means? I want to use a state node in my process, which means I hope the process go into this node then wait for signal from external systems. From my understanding, the external system means an application like web-console in the suite, but the other type, like java program, is also possible. External system will integrate with JBPM engine though JbpmConfiguration and then get JbpmContext then get ProcessDefinition, instance and token and so on. If above understanding is correct, Here's my second question. I think it should be common that there are more than one external system using the same jbpm engine and work on the same process instance, like that there are one web-console run a processinstance and go into a state node and wait for another external system, a java program to trigger the token.signal(). I try to do like this using the 3.2.2 suite, but if I try to run these two external system currently, there will be an error prompt me that the hsqldb was locked by a process so one of the external system can't operate currectly. This is where my confusion comes from. Is this the problem of Hsqldb or my use case is not supporteb by jbpm? Thank you very much for your attention and look forward your suggestion. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4102393#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...