At bottom it is convenient tool to store different documents, links, notes, workflows with business objects assigned. Business trip, personnel number, absence could be a business object. It looks like that:
Customizing is pretty simple. I’d say most of the features is already set by default.
Some inputs for curious guys. Services are defined in SGOSATTR table.
Data is stored in two areas depends on service. Document Business Store service stores data in Archive Link database, which is set in OAC2, OAC3 transactions. Attachment Store stores data in Knowledge Database (SOFFCONT1 table).
You can use BADI to manage service: GOS_SRV_REQUEST, GOS_SRV_SELECT.
And here is a program to verify settings: RSGOSCHECK.
Could help : http://wiki.scn.sap.com/wiki/display/TechTSG/Generic+Object+Services+%28GOS%29+Troubleshooting+Guide