This article presents a perishable (s; S) inventory system under continuous review at a service facility in which a waiting hall for customers is of nite size M. The arrival instants of customers to the service station constitutes a Poisson process. The life time of each items is assumed to be exponential. All arriving customers demand the rst "essential" service, whereas only some of them dema...

 This study considers a system of multi-server queues with two classes of impatient customers: high-priority and low-priority. Customers join the system according to a Poisson process and customers may abandon service after entering the queue for an exponentially distributed duration with distinct rates. In this paper, we consider last come-first served (LCFS) and first come-first served (FCFS...

queueing models with impatient customers, server vacations and a waiting server. The arrival process is assumed to be Poisson. The server is allowed to take a vacation whenever the system is empty after waiting for a random period of time. Whenever the server is on vacation, each customer in the queue independently of the other customers sets up an impatience timer. If the server does not retur...

This paper analyzes a discrete-time $Geo/Geo/c$ queueing system with multiple working vacations and reneging in which customers arrive according to a geometric process. As soon as the system gets empty, the servers go to a working vacations all together. The service times during regular busy period, working vacation period and vacation times are assumed to be geometrically distributed. Customer...

We consider a multiserver queueing system with two classes of customers: a type 1 (narrow-band, NB) customer requires a single server, while each type 2 (wide-band, WB) customer requests n of the rn servers (n is not random). Servers allocated to a type 2 customer are seized and released simultaneously. Service times are exponentially distributed with mean l/p, for type i customers (i = 1,2). B...

We consider an M/G/1 retrial queue with general retrial times and single working vacation. During the working vacation period, customers can be served at a lower rate. Both service times in a vacation period and in a service period are generally distributed random variables. Using supplementary variable method we obtain the probability generating function for the number of customers and the ave...

In this paper we study a queueing model of assembly-like manufacturing operations. This study was motivated by an examination of a circuit pack testing procedure in an AT&T factory. However, the model may be representative of many manufacturing assembly operations. We assume that customers from n classes arrive according to independent Poisson processes with the same arrival rate into a singles...

banking and financial services are important parts of the service industry. quality of service in the banking industry has a close relationship with customer satisfaction service system. banks could create competitive advantage by increasing customer satisfaction and reduce costs in today's competitive environment. this paper presents a decision-making model to obtain optimum tasks assigne...

For a K-stage cyclic queueing network with N customers and general service times we provide bounds on the n departure time from each stage. Furthermore, we analyze the asymptotic tail behavior of cycle times and waiting times given that at least one service time distribution is subexponential.