Abstract
This paper constructs a dynamic model of a general congestion-prone system using a nonlinear differential equation to represent the relation between throughput and the system load. Although the model is not stochastic, it can give a good approximation of the dynamics of oversaturated or undersaturated system operation. The model is used to study the stability and transient behavior of a congestion-prone system and to analyze policies for the control of congestion in a simple optimal control model.