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...

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...

we consider an m/g/1 queue with regular and optional phase vacation and withstate dependent arrival rate. the vacation policy is after completion of service if there are no customers in the system, the server takes vacation consisting of k -phases, each phase is generally distributed. here the first phase is compulsory where as the other phases are optional. for this model the supplementary var...

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...

We consider an M/G/1 queue with regular and optional phase vacation and withstate dependent arrival rate. The vacation policy is after completion of service if there are no customers in the system, the server takes vacation consisting of K -phases, each phase is generally distributed. Here the first phase is compulsory where as the other phases are optional. For this model the supplementary var...