Hi, Yes, aopc will modify the original class file, adding code to this file. For this code to work, auxiliary classes are need, which are the extra class files you are seeing. Any AOP framework increases the size of the basis program, since all of them add code to the program. I don't think, however, that this generates a considerable impact, unless you have to follow very strict memory space requirements. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4235094#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...