The Mean Queue Time Approximations Of General Tandem Queues With Multi-server

Tandem queueing system is a basic structure of queueing network in which all stations are dependent.Except for tandem queues with Markovian property or constant service times,it is difficult to calculate the mean queue times of tandem queues.The current research is limited to the approximate analysis.Many researchers have presented approximation methods of mean waiting time without comparison among them,and there is no specific analytic expression for the mean queue time of the general tandem queue with multi-server.By simulation,we figure out regulations of the mean queue time and put forward the approximate expression of the mean queue time in tandem queues with multi-server in this paper.Firstly,we propose the numerical comparison of mean waiting time approximations of M/G/m queues.Then,a method to estimate the mean queue time of tandem queue is proposed.The main work of this paper is as follows:? For the four popular approximation methods of the mean queue time in the M/G/m queues,we compute the approximations of mean queue time of various systems with different parameters.By comparing the approximations of the mean of queue time with the simulation results,the accuracy of the four methods is analyzed.? We give an expression to estimate the mean queue time of two work stations of production system by using the properties of the intrinsic ratio and contribution factor,and present a calculation method of mean queue time of general tandem queues with multi-server.In the production system,we may use the properties of intrinsic ratio to get more accurate approximation of the mean queue time.