image/svg+xml customer arrival time service time Standard assumptions - Curse of dimensionality state: Higher dimensional Markov models Computational approach to “rate in = rate out” equations Truncate an infinite number of equations Algebraic formulation Higher dimensional Markov models Classical analysis: M/M/n system - Throughout this talk, we use For sufficiently large t Key challenge: No longer independent Poisson We start with a discrete service-time distribution: Number in system X(t) This suggests for some quantile cross-covariances . where Remark: Iglehart 1965 Borovkov 1967 M/G/ Implication: G/G/ Factory Physics (Hopp/Spearman 2011) proposes Sakasegawa: Suggested approximation: We seek the smallest search over n yields search over n yields 12am 5am 10am 3pm 8pm 1am 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Manhattan 2006, health.ny.gov 310 arrivals per week our data 0 2 4 6 8 10