IV · Queueing theory

M/M/1 queue

What it is

Single server, Poisson arrivals (rate λ), exponential service (rate μ). Average wait W = 1/(μ−λ).

Where it lives

Initial latency models for any single-bottleneck system. The clean baseline before reality intrudes.

The key insight

The (μ−λ) denominator: as utilisation approaches 1, wait time → ∞. You cannot run a server at 99% utilisation.