Simulation models are usually used in situations where complex or complicated systems and processes need to be analyzed. The main advantage of the simulation modelling is the fact that it is realized in virtual reality (in simulation software) without the necessity to change the real processes. In this article the process of the model creation, verification and validation is described on the example of the Cisco routers production line in company Foxconn CZ. One part of the production line is modelled in SIMUL8 software. The main aim is to verify options for the line balancing improvement. For the activities’ duration times the estimation of the probability distribution was made in R software on the basis of real data or via the experts’ estimate. After the process bottleneck findings according to the simulation models’ results the changes in the production process were suggested.