“…There is a vast literature on this subject, but our focus is quite different. Work by Ibrahim and Whitt [14,15,16,17] develops new real-time estimators for estimating delays in various queueing systems. The work of Armony and Maglaras [3], Guo and Zipkin [9], Hassin [11], Armony et al [4], Guo and Zipkin [10], Jouini et al [20,21], Allon and Bassamboo [1], Allon et al [2], Ibrahim et al [18], Whitt [31] and references therein analyzes the impact of delay announcements on the queueing process and the abandonment process of the system.…”