Rule Definition
Since stateful session beans cannot be pooled and reused like stateless beans, there is a real danger of accumulating too many of them if the remove method is not implemented or if this method is not called.

Remediation
Call this method from the client side

Violation Code Sample

@Remote
public interface MyRemoteBean {
    public int aMethod();
    public void removeMethod();
}

@Stateful
public class MyBean implements MyRemoteBean {
    ...
    public int aMethod() {
        ...
    }

    @Remove
    public void removeMethod() {
        ...
    }
}

public class Client { // VIOLATION

    private static @EJB MyRemoteBean myClientBean;

    public static void main(String[] args) {
        Client client = new Client(args);
        client.callServer();
    }

    public Client(String[] args) {}

    public void callServer() {
        try {
            int res=myClientBean.aMethod();
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}

Fixed Code Sample

@Remote
public interface MyRemoteBean {
    public int aMethod();
    public void removeMethod();
}

@Stateful
public class MyBean implements MyRemoteBean {
    ...
    public int aMethod() {
        ...
    }

    @Remove
    public void removeMethod() {
        ...
    }
}

public class Client {

    private static @EJB MyRemoteBean myClientBean;

    public static void main(String[] args) {
        Client client = new Client(args);
        client.callServer();
    }

    public Client(String[] args) {}

    public void callServer() {

        try {
            int res=myClientBean.aMethod();
            myClientBean.removeMethod(); // FIXED
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}

EJB 3 in Action (ISBN 1-933988-34-7) page 94 http://what-when-how.com/enterprise-javabeans-3/stateful-session-beans-ejb-3/