SUM 15 - SL Common GUI ?

Hi,

How to use the browse -based SL Common GUI.  Here they comes with DMO ( Downtime migration option) . Actually I want to go with upgrade Support pack. When I go with SUM 15 user guide.. it describe about the DB system copy using SWPM.

i don't know why I have to go with SWPM ..DB system copy ?

Any one please clarify me and let me know how to access the SL Common GUI.

Regards

Jeevagan