This paper studies alternative ways to manage a multi-server system such as a telephone call center. Three alternatives can be described succinctly by: (i) blocking, (ii) reneging and (iii) balking. The rst alternative { blocking { is to have no provision for waiting. The second alternative is to allow waiting, but neither inform customers about anticipated delays nor provide state information ...

We examine an M/G/1 queue with several queueing disciplines. After reviewing some background material in probability theory, we consider a first-come first-served queue. Next, we examine an absolute priority queue, where high priority customers are always selected for service over lower priority customers, regardless of how long the latter have been waiting. We also review a method for calculat...

This paper studies the operating characteristics of an MX/Hk/1 queueing system under multiple vacation policy. It is assumed that the server goes for vacation as soon as the system becomes empty. When he returns from a vacation and there is one or more customers waiting in the queue, he serves these customers until the system becomes empty again, otherwise goes for another vacation. The brea...

We consider a two-heterogeneous-server queueing system with Bernoulli vacation in which customers arrive according to a Markovian arrival process MAP . Servers returning from vacation immediately take another vacation if no customer is waiting. Using matrix-geometric method, the steady-state probability of the number of customers in the system is investigated. Some important performance measure...

Resources including various assets of supply chains, face random demand over time and can be shared by others. We consider an operational setting where a resource is shared by two different classes of customers, the primary class (existing customers) and the secondary class (new firms) customers, under a service level based pricing contract with the secondary class customers which specifies the...

ABSTRACf. This investigation deals with a multi server queueing model in which customers leave the system in the same chronological order in which they arrive. The customers are assumed to arrive in Poisson fashion from two infinite priority and ordinary sources and their service times are identical and exponentially distributed. The priority customers may wait but the ordinary customers are lo...

This paper studies a multiclass queueing system with endogenous abandonments where congestion a↵ects customers’ abandonment behavior and vice versa. Our model captures this interaction by developing two closely related models: an abandonment model and a queueing model. In the abandonment model, customers take the virtual waiting time distribution as given. Class k customers receive a reward rk ...

In this paper, we study three delay systems where different classes of impatient customers arrive according to independent Poisson processes. In the first system, a single server receives two classes of customers with general service time requirements, and follows a non-preemptive priority policy in serving them. Both classes of customers abandon the system when their exponentially distributed ...

This paper presents an algorithmic procedure to calculate the delay distribution of (im)patient customers in a discrete time D-MAP/PH/1 queue, where the service time distribution of a customer depends on his waiting time. We consider three different situations: impatient customers in the waiting room, impatient customers in the system, that is, if a customer has been in the waiting room, respec...

background and purpose: preoperative fast is the essential part of preoperative care for those patients who are candidates for elective surgery. fast prolongation results in side effects such as: sweating, irritability, decrease in blood sugar and restlessness. despite the noticeable changes in fasting guidelines and their application in many countries, it seems that in iran, these rules are no...