As you may now know, you can store many kinds of variables on the jbpm, since in the desing you're only giving names to them, and not setting types. Although you do can make some validation of this variables with bean shell, I would recomend that you make the validations before you put them on jbpm, for example with Validator in case you are using JSF. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4053785#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...