DESIGN AND IMPLEMENTATION OF CQNET: A PACKAGE FOR PERFORMANCE ANALYSIS OF CLOSED QUEUEING NETWORKS

Abstract

A software package 'CQNET' for analysis of closed queueing network has been developed in the present dissertaltion. This package analysis any closed queueing network using analytical and simulated models based on First Come First Served (FCFS) Scheduling. In this work an approximate procedure for the performance analysis of closed queueing network with N stations and K number of total jobs is developed and implemented. Each station has a single server, an exponentially distributed service time with certain mean value and infinite capacity. The procedure allows to study the behaviour of this system by stepwise increasing the number of jobs in the entire network. The package supports basic data structures to define entities and provides procedures for creating and managing these entities and for displaying output of the simulation. The central server model and virtual circuit model have been analysed by using this package. Inference regarding various performance measurements are made and parameters such as mean delay, throughput of network, mean queue length are calculated. This algorithm is faster than other algorithms developed by [11], [16], [17], as no computation of product terms and normalization constants are made in this approach. The Analytical results are compared with simulated values and it is observed that the percentage of error is between 2.5 and 11.5.