It's probably a good practice to separate out your Entity beans into their own JAR; each persistence unit is scoped to that JAR alone per the spec. I generally like to give each of my "services" (which may be JMX, Stateful, or Stateless EJBs) its own JAR, each unique collection of Entity Beans per persistence unit its own JAR (read: if 3 persistence units, 3 JARs for Entities), and a "common" JAR for standard java classes. Then I throw all these into an EAR with a proper application.xml in META-INF, explicitly defining each of the components above. In the end, it'll come down to whatever works best for your system, and how you plan on deploying your components (All at once, always? Lots of dependencies? Or as independent modules that may be added or removed on a whim?) S, ALR View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3995207#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...