DETERMINE THE OPTIMAL NUMBER OF SPARE PARTS USING FUZZY QUEUING MODEL WITH LIMITED SOURCE

Abstract

Queuing models with limited source have many applications in practical situations and seen frequently in operation and maintenance of vehicles. Due to uncontrollable factors, parameters of queuing issues with limited resource may be inconsistent. So the fuzzy queuing model with finite resource can be closer to reality. In this article in order to design the system and determine the optimal number of spare parts, we seek to minimize the total cost function while the repair rate and the input rate are fuzzy numbers; also the cost function includes the cost of maintenance spare pieces and the cost of system deactivation. After calculating the value of cost function for different number of spare parts, we compare the value of the obtained function by using Liou-Wang and Nakamura methods and concluded that the keeping of how many spare parts are economical.