SLA (service level agreement) specification languages are designed to express monitorable contracts between a provider and a consumer of a service. It is of interest to determine if one can derive predictive models, e.g., a discreteevent stochastic model, for SLAs expressed in such a language, if possible in automated fashion. For this purpose, we study in this paper the mapping of the Web Serv...

This paper deals with finite-population, single and multi-server queueing systems with two classes of vacation mechanisms : station vacation and server vacation. In the first one, all the servers take vacation simultaneously whenever the system becomes empty, and they also return to the system at the same time, i.e., station vacation is group vacation for all servers. For the second class of va...

We consider the robust design and control of call center systems with flexible interactive voice response (IVR) systems. In a typical call center equipped with an IVR system, customers are handled first by the IVR system, which is a computerized system that often enables customers to self-serve. Those customers whose service cannot be handled by the IVR system are sent to the second stage to be...

Professor Naoki Ikegami’s “Fee-for-service payment – an evil practice that must be stamped out” summarizes many of the failings of alternatives to fee-for-service (FFS) payment systems. His article also offers several suggestions for improving FFS systems. However, even powerful arguments against many of the alternatives to FFS, does not make a convincing argument for FFS systems. In addition, ...

This paper deals with the stability of periodic polling models with mixed service policies. The interarrivals to all queues are independent and exponentially distributed and the service and the switch-over times are independent with general distributions. The necessary and suucient condition for the stability of such polling systems is established. The proof is based on the stochastic monotonic...

A queue is a waiting line (like customers waiting at a supermarket checkout counter); queueing theory is the mathematical theory of waiting lines. More generally, queueing theory is concerned with the mathematical modeling and analysis of systems that provide service to random demands. A queueing model is an abstract description of such a system. Typically, a queueing model represents (1) the s...