In reply to ABD_91:
I believe you are misunderstanding a lot of things regarding ports/exports.
analysis_ports and analysis_export belonging together. On the same hierchy level you can only connects ports iwth exports. Only on different hierarchy levels you can connect ports with ports and exports with exports or imps. the ports are requring a method they are calling and the exports/imps have to provide this method. That is very simple but powerful.