An M/M/1 queueing system with second optional service and unreliable server is studied. We consider that the server works at different rate rather than being idle during the vacation period. The customers arrive to the system according to Poisson process with state dependent rates depending upon the server’s status. All customers demand the first essential service whereas only some of them dema...

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 investigation deals with MX/G/1 queueing model with setup, bulk- arrival, loss-delay and balking. The provision of second optional service apart from essential service by an unreliable server is taken into consideration. We assume that the delay customers join the queue when server is busy whereas loss customers depart from the system. After receiving the essential service, the customers m...

We study an M/G/1 queueing system where the arrival follows Poisson Process. The server provides service in two stages, the first stage service is essential and the second stage of service is optional. If the system is empty then the server goes for a vacation of random duration and after returning from vacation the server decides to take a second vacation which is optional. When the server is ...

We study an M/G/1 queue with second optional service. Poisson arrivals with mean arrival rate λ (> 0), all demand the first ‘essential’ service, whereas only some of them demand the second ‘optional’ service. The service times of the first essential service are assumed to follow a general (arbitrary) distribution with distribution function B1(v) and that of the second optional service with gene...

In this paper, we study a single server Markovian queue with state dependent accessible services, reneging and feedback of customers. The server can accommodate at the most $d$ customers in the service station, after which the new arrivals have to wait in the primary queue of infinite waiting space. All arrivals demand First Essential Service (FES), after completing FES, customers decide to joi...

The aim of this paper is to analyze Bi-level threshold policy of M/(G1, G2)/1 with single vacation (SV) queue in a fuzzy environment. A mathematical Non linear programming (NLP) method is used to construct the membership function of the system characteristic in which the batch arrival-rate, expected group size, setup time, vacation time, service time for first essential service(FES), service ti...

doi: 10.5829/idosi.ije.2012.25.03c.06