performance evaluation and improvement of queuing system in iran khodro agency, a case study

today, in a competitive market, service organizations and producers have a great attention to optimization and customer satisfaction in order to become competitive. service organization must reduce the number of arrival, waiting time and service time in the queue to increase the customer satisfaction. in this paper by the aim of queuing theory we analyze the optimal amount of increment in a repair shop space and number of purchasing advanced equipment in one of the branches of iran khodro, automobile producer and assembler in iran, in order to reduce customer waiting time then we fine m/m/s ، m/m/s/s ، m/m/s/k models that fit to our analysis. also we do the data sensitivity analysis in each part of the repair shop with respect to the cost of each situation and the effect of it on the whole system then we specify the economic optimal service level in order to rearrange the stations in this branch.