Hello,
Pop up at the end of notification will give you th idea whether your notification belongs to internal activity or external one. Secondly, if you want to assign vendor,manufacturer orany other third party in loo you need to set up the Workflow and maintain there mail ids in masters like in Vendor master, Customer master etc.
Defect recording ad tracing of activity is purely the part of QM- QA deptt. and performing the corrective task and activity is purely the responsibility of concern Deptt.
Regards