Hi Esteban, I'm sorry to contradict you, but the ksession is not the same in main and sub-process.
I take a test with a variable and the resul is different
org.drools.runtime.process.WorkflowProcessInstance process = (org.drools.runtime.process.WorkflowProcessInstance)kcontext.getProcessInstance();
System.out.println("Risultato Processo Principale: "+process.getVariable("risultato"));
.... so this means that in the main process I can't use the ksession on the sub-process.
at this point... what is the point of using of a sub-process?? is not very useful!!!