Abstract. The paper presents original object oriented programming system ARS for modelling and simulation queuing systems. Programming system was developed in programming language C++. It establishes connection with intrinsic, but also with other Windows programming packages, in a simple way, through object oriented environment. Basic characteristics and possibilities of programming system, as well as comparative analysis of simulators: mathematical model (analytical solution) -GPSS/H -ARS, on the example of closed queuing network in the paper is given. The signifi cant application for computer performance evaluation is reported.