Layered networks I: From manufacturing plants to queueing networks
Manufacturing plants convert raw material into a final product. Think of cars, where the production line consists of a large number of phases to put all the different parts together into a working car. Big machines in such a plant perform the processing steps in different phases, which often have to be done in a specific order.
Traffic congestion: Pigou's example
In network congestion models, we make some simplifying assumptions that make our life easier. In a large-scale system, each individual driver contributes a tiny amount to congestion, if we assume that every car controls the same amount of traffic.