Q.Notification-Person responsible

Hi ,

Please guide me How & Who will assign TASKS &  ACTIVITIES in QM notification.

l Ex: If in our plant my self (K1) is responsible for Inward inspection for Bolts(Material :M1) ;receive from vendor V1, responsible person in purchase department for bolts is P1.&found a defect as "Bolt head damage"

please guide me with above generic example in a SAP driven plant ,who will assign the tasks / Activities& again who completes Tasks & activities.(Flow) 

Thanks,

karthik