This paper is concerned with a scheduling problem that occurs in service systems, where customers are classified as ‘ordinary’ and ‘special’. Ordinary customers can be served on any service facility, while special customers can be served only on the flexible service facilities. Customers arrive dynamically over time and their needs become known upon arrival. We assume any service, once started,...

In this paper, we analyze a discrete-time preemptive resume priority queue. We consider two classes of customers which have to be served, where customers of one class have preemptive resume priority over customers of the other. Both classes contain customers with generally distributed service times. We show that the use of probability generating functions is beneficial for analyzing the system ...

In this paper a single server preemptive priority queuing system consisting of two types of customer units with Poisson arrival, exponential service time distribution and exponential vacation is analyzed. Two type of customer units of which higher priority units of unlimited Poisson input are served by bulk service rule and limited Poisson input of low priority units served singly. The bulk ser...

We derive the performance measures for non-priority customers in a priority single-server queue with two types of Markovian arrival processes (MAPs). One type of customers has preemptive resume (or repeat) priority over the other. We regard the model with two types of MAP arrivals as an MAP/SM/l queue with only non-priority customers arrivals, semi-Markovian service times and some server vacati...

Consider aI~lUlti-priority, nonpreemptive, N-server Poisson arrival queueing system. The number of servers requested by an arrival has a known probability distribution. Service times are negative exponential. In order to save available servers for higher priority customers., arriving customers of each lower priority are deliberately queued whenever the number of servers busy equals or exceeds a...

This paper introduces a new priority mechanism in discretetime queueing systems that compromises between first-come-first-served (FCFS) and head-of-line (HoL) priority. In this scheduling discipline which we dubbed slot-bound priority customers of different priority classes entering the system during the same time-slot are served in order of their respective priority class. Customers entering d...

A retrial queueing system with two types of batch arrivals, called type I and type II customers, is considered. Type I customers and type II customers arrive in batches of variable sizes according to two different Poisson processes. Service time distributions are identical and independent and are different for both types of customers. If the arriving customers are blocked due to the server bein...

nowadays, managing the relations between customers is a fundamental necessity in activities leading to the promotion in the chain of an organization. in fact, customers satisfaction and quality of services are considered as the vital issues in most industries and services. after-sales services will also become more important in near future in iran and the survival of domestic automobile industr...

We consider strategic arrivals to a FCFS service system that starts service at a fixed time and has to serve a fixed number of customers, e.g., an airplane boarding system. Arriving early induces a higher waiting cost (waiting before service begins) while arriving late induces a cost because earlier arrivals take the better seats. We first consider arrivals of heterogeneous customers that choos...