Hi Saifudin,
Activity type is controlled by Control key.
In standard system PS01 is for internal process, PS02 & 06 is relevant for externally proocess (02 for material & 06 for pure service w/o material).
So you need to check & change this control key, so that system will compel you further details like purch org, service no etc.
Hope this satisfy your query.
Regards,
VINOD.V