The distributional form of Little’s Law and the Fuhrmann-Cooper decomposition

For certain classes of customers, the ergodic number of customers in system (queue) and the ergodic time spent in system (queue) are related by a distributional form of Little’s Law. When such a class satisfies modest auxiliary conditions, a structurally simple decomposition of the number in system of the form of Fuhrmann and Cooper is present. This decomposition is implemented for several queueing systems and is shown thereby to provide a degree of unification to queueing theory.