In this paper, we consider a discrete-time single-server finite-buffer batch arrival queue in which customers are served in batches according to a general bulk-service rule, that is, at least ‘a’ customers are needed to start a service with a maximum serving capacity of ‘b’ customers. The server takes a (single and multiple) vacation as soon as the queue length falls below ‘a’ at the completion...

Modern computer systems are based on a wide variety of software servers, such as web servers, application servers, database servers, and mail servers. The typical software architecture of such servers includes a set of processes or threads that serve requests submitted to the server. Requests that arrive at the server and find all threads busy, are placed in a queue. Threads that are busy execu...

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...

This paper deals with multi-component machine repair model having provision of warm standby units and repair facility consisting of two heterogeneous servers (primary and secondary) to provide repair to the failed units. The failure of operating and standby units may occur individually or due to some common cause. The primary server may fail partially following full failure whereas secondary se...

We study N-queues single-server fluid polling systems, where a fluid is continuously flowing into the queues at queue-dependent rates. When visiting and serving a queue, the server reduces the amount of fluid in that queue at a queue-dependent rate. Switching from queue i to queue j requires two random-duration steps: (i) departing queue i, and (ii) reaching queue j. The length of time the serv...

Customers arrive to a single service queue according to a Poisson process with rate l, from which they are routed to two parallel heterogeneous and exponential servers whose ra.tes are 1'1 > #2· Customers are released from the system after service completion, according to their arrival order a requirement introducing additional resequencing delays. Customers which are delayed due to resequencin...