Simulation Of Logistics Processes In Flexible Manufacturing Systems

Four models of a flexible production system built on the basis of the queuing theory have been considered, this theory presenting the flexible production system itself as a single-channel queuing system with changeover and loss of requirements. It is assumed that the input of all four models of the flexible manufacturing system receives a Poisson flow of orders at a rate of λ > 0 per unit of time. The order processing takes place in the order they are received, and the order processing time obeys the exponential distribution law with the parameter μ > 0. The device has a feature consisting in the fact that having processed all the orders available in the system, in order to resume work, it needs readjustment aiming to prepare the equipment for completing a new batch of orders. For all models, it is assumed that the duration of the changeover has an exponential distribution with the parameter v > 0. For the systems described, characteristics have been found which are used to determine the system operation basic parameters, namely the probability of equipment being on changeover, the probability of receiving a denial for service and the average queue length. These characteristics can be used in solving the problem of optimal control of flexible manufacturing systems.