Book:OTRS 3.0 - Admin Manual/Chapter 9

Abstract
From OTRS 2.1 on, it is possible to assign a person as being responsible for a ticket, additionally to its owner. Moreover, all activities connected with the ticket can be watched by someone other than the ticket owner. These two functionalities are implemented with the TicketResponsible and TicketWatcher features, and facilitate the assignment of tasks and working within hierarchical team structures.