Stochastic Simulation of Markov Modulated Finite-Source Queues

The simulation tool lcpSim can be used to investigate special level crossing problems of queueing systems of type HY POk/HY POr/1//n embedded in different Markovian environments. Our observed system consists of n heterogeneous machines (requests) and a server that ”repairs” the broken machines according to the most commonly used service disciplines. We specify a maximum number of stopped machines for an operating system and our aim is to give the main steady-state performance measures of the system, such as server utilization, machine utilization, mean waiting times, mean response times, the probability of an operating system and the mean operating time of the system. These values can be calculated by lcpSim (level crossing problem Simulation) for several types of operating and service times of the machines and for different random environments. The simulation uses the Law–Carson algorithm to provide confidence intervals for the main performance measures of the investigated system. We developed the Java language version of the lcpSim program last year. Besides the main application this version also contains an input generator (inputGen), both with user-friendly graphical interfaces. The effects of each service discipline on the performance measures of the given systems can easily be observed on the diagrams generated from the output files of the lcpSim program in terms of the increasing number of machines.