This paper analyzes an M/M/2 queueing system with two heterogeneous servers. Both servers goes on vacation when there is no customers waiting for service after this server 1 is always available but the other goes on vacation whenever server 2 is idle. The vacationing server however, returns to serve at a low rate as an arrival finds the other server busy. The system is analyzed in the steady st...

a two server queueing system with single and batch service is considered in this paper. the arrival process is assumed to be poisson and the service rate follows an exponential distribution. server-i serves the customers in both single and batch service, while server-ii serves the customers in batch service only. the laplace transform of the transient and steady state behavior of the model is c...

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...

In this paper we develop a multi-objective model to optimally control the lead time of a multistage assembly system. The multistage assembly system is modeled as an open queueing network, whose service stations represent manufacturing or assembly operations. The arrival processes of the individual parts of the product, which should be assembled to each other in assembly stations, are assumed to...

In this paper, we consider the batch arrival of customers to a transport station. Customers belonging each category is considered as single entity according BMMAP. An Erlang clock order m starts ticking when vessel reaches When Lth stage reached, an for next placed. The lead time follows exponential distribution. There are two types rooms in system: waiting and service station vessel, respectiv...

This paper studies a discrete-time queueing system in which customer who enters the with server occupied may choose to go retrial group or begin its service displacing that was server. If is idle arriving begins immediately. Retrial and times are general, only repeated can directly one situated at first place of group. A complete study model has been curried out noting specially analysis recurs...