Hi cssatheesh, I suppose from your questions, that you are searching a process-management-engine for your java project and that you have already evaluated JBoss Drool ( I insinuate that, because of the "rulecentric" scope of your questions :D) As I'm doing the same task for one of our projects, I'm trying to share my insights about both engines with you. My first finding is that both engines (jbpm and drools flow) have their own right and their own focus in implementing a workflow-management-engine. Drools is a very powerful rule-centric engine which has integrated lot's of functionality provided to Business-Rules, while Jbpm is a lightweight solution concentrating on the java world. Both has it's advantages, but Drools is (in my opinion ;) ) a solution which is useful if your project benifits from a very high integration of buisiness-rules. It perfomes lesser than jbpm in the java-world and is more error-prone because it's complex architecture. I'm trying to give you a deeper insight in your questions but i must admit that my insights are restricted. 1) Yes, for both libraries but with a restriction, you have to use the esb or java-class actions to invoke them in jbpm, while you have to create a workitem or a java-action in drools. 2) Yes, this is were Jbpm is clearly superiour to Drools, you can intstanciate a method of a random pojo, with chosen parameters using the java-action, were you have to use a workItem or a java-drools-action in drools (which is quite less flexible). 3)Yes you can use hql and sql actions, and call stored procedures with your java classes invoced by a java action. For drools you have to use a workItem or a java-drools-action 4 + 5)Neither jbpm nor drools implement a default webservice to call a process (at least I don't know such a default webservice), but it's quite easy to implement a webservice calling the processengine, especially if you use Jboss Seam or a library like axis2. At least there is nothing about rules in Jbpm ;) , you have to call a rule-engine like drools for this purpose, but this might be more efficient if your development is java-centric and is using relativly few rules. I hope this helped, CU Jan View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4253213#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...