“…[Also see Roes, P. B. M. (1962) and Shyu (1962)]. Some of the special cases studied for the time dependent behavior of the queue length process are M/M/s [Karlin and McGregor (1958), Saaty (1960), Jackson and Henderson (1966)J, GI/M/2 [Bhat (1965), Arora (1962) who considers a specialized arrival schemeJ and GI/M/3 [Bhat (1966)J. Mention can also be made of studies of a quite general nature, in terms of the waiting times of the nth arrival, like those of Kiefer and Wolfowitz (1955), Pollaczek (1961) and Presman (1965).…”