I'm not quite sure what your question is. But if it is something like:
"Of what use is a local client in a distributed system (EJB)?", my answer is:
A "local client" of an enterprise bean, i.e. a client that uses local home and component interfaces of an enterprise bean, usually describes another enterprise bean within the same application, for example, a session bean using an entity bean within the same application.
Note that the local client can be an EJB or it can easily be a servlet. What is important is that a local client must be in the same app as the bean it calls, ie you must include the client code in the same the EAR file when you build. When you deploy the EAR file, all the code will be in the same JVM. This is essential as local calls involve pass-by-reference, so the local client and the bean providing the local client view must be collocated.