“…For workload, availability of a resource is considered most often ( 10studies) [4,26,27,34,35,43,52,64,68,72]. Fourteen studies consider the role attribute [5,7,12,15,22,24,34,35,50,59,62,63,65,69]. We found that the role is most often encoded directly as an attribute (9 studies) [5,7,15,22,24,35,50,62,63].…”