In this investigation, we study the performance characteristics of (m,M) machining systems having warm spares and two heterogeneous servers. The first server is permanent and available full time in the system, whereas the second server takes vacation according to the specific threshold policy. In some real time systems, spares may or may not replace/switch in the system whenever an operating un...

In this paper, we analyze a machine repairable system with warm spares and two repairmen. The first repairman never takes vacations. The second repairman leaves for a vacation of random length when the number of the failed units is less than N. At the end of a vacation period, this repairman returns back if there are N or more failed units accumulated in the system. Otherwise this repairman goe...

We consider a k-out-of-N reliability system with identical components having exponential lifetimes. There is a single repairman who attends to failed components on a firstcome first-served basis. The repair times are assumed to be of phase type. The system has K spares that can be used according to a probabilistic rule to extend the lifetime of the system. The system is analyzed using Markov ch...

We consider a machine repair problem with server breakdowns, in which an unreliable server (repairman) operates the threshold recovery policy. When there are no failed machines in the system, the server leaves for a vacation. If the server returns from a vacation to find no failed machines in the system, he/she immediately takes another vacation. And the server continues in this manner until he...

We consider a system of two parallel queues sharing a common arrival process, where the arriving customers select which queue to join based on a generalized Join the Shortest Queue ( ) policy. We assume that both servers run at the same speed. However, we assume that departing customers face some additional delay after leaving the system, and that this downstream delay is different between the ...

Abstract: The present investigation deals with the multi component machine repair problem by including the concepts of reneging and interdependent controlled rates. We consider a machining system consisting of M operating units, S1 and S2 warm spares of two kinds and a repair facility having R permanent repairmen and r additional removable repairmen. When all the spares are used and the operati...

We consider an extension of the classical machine-repair model, also known as the computer-terminal model or time-sharing model. As opposed to the classical model, we assume that the machines, apart from receiving service from the repairman, supply service themselves to queues of products. The extended model can be viewed as a two-layered queueing network, of which the first layer consists of t...

this paper analyzes a controllable discrete-time machine repair problem withl operating machines and two repairmen. the number of working servers can be adjusteddepending on the number of failed machines in the system one at a time at machine's failure orat service completion epochs. analytical closed-form solutions of the stationary probabilities ofthe number of failed machines in the sys...

This paper presents a discrete-time single-server finite buffer N threshold policy queue with renewal input and discrete Markovian service process. The server terminates service whenever the system becomes empty, and recommences service as soon as the number of waiting customers in the queue is N . We obtain the system-length distributions at prearrival and arbitrary epochs using the supplement...

This paper presents the analysis of a renewal input  finite buffer queue wherein the customers can decide either to  join the queue with a probability or balk. The service process is Markovian service process ($MSP$) governed  by an underlying $m$-state Markov chain. Employing the supplementary  variable and imbedded Markov chain techniques,   the steady-state system length distributions at pre...