Thoroughly revised and expanded to reflect the latest developments in the field, the fourth edition of Fundamentals of Queueing Theory illustrates the wide-reaching, fundamental concepts in queueing theory and its applications to diverse areas such as computer science, engineering, business, and operations research. It takes a numerical approach to understanding and making probable estimations relating to queues, with a comprehensive outline of simple and more advanced queueing models. Newly featured topics include retrial queues, approximations for queueing networks, numerical inversion of transforms, and determining the appropriate number of servers to balance quality and cost of service.