From computer science to service science: Queues with human customers and servers

Professor Leonard Kleinrock has made key contributions during the initial stage of development in computer communication networks from several aspects. One of them is the ingenious application of queueing theory to the performance evaluation of communication networks. Queueing theory is still useful in contemporary service systems having human customers and servers as precious resources. However, some new theoretical development is needed to cope with human service systems. In this article, the potential of queueing theory is discussed in the scope of emerging service science. We begin with a snapshot of Professor Kleinrock’s laboratory in the early 1980s. We then review the performance metric called power worked out by Kleinrock as it determines the optimal input rate in a service system. As an example of service science for healthcare, we show modeling of obstetric patient flow in a hospital by means of Little’s law and a network of M/M/m   and M/G/∞∞ queues.