The second course in queueing, picking up where M/M/1 leaves off. Multiple servers and Erlang C, why pooling two lines into one cuts the wait by 57% at identical load, finite capacity and blocking, and Erlang B for loss systems with no waiting room at all. Then the variability half: the Pollaczek-Khinchine formula, why deterministic service waits exactly half as long as exponential at the same mean, Kingman's approximation for when you know only means and coefficients of variation, heavy traffic and the 1/(1-rho) blowup, and the waiting-time paradox. It closes with priority and the conservation law that says priority moves waiting rather than removing it, scheduling disciplines, balking and reneging, Burke's theorem, and Jackson networks. Scoped against probability and stochastic, which own Kendall notation, M/M/1, Little's law, birth-death balance and the Poisson process; none of that is repeated here.
Free to start · adaptive placement finds your level · reviews timed so it stays learned.
Every idea is taught with motivation and a worked example before the drills, and an FSRS spaced-repetition engine schedules each review for the moment just before you'd forget it. A short placement check finds what you already know, so you start Queueing Theory exactly where it's useful.