Multi-impact modeling is a challenge in the simulation of processes such as shot peening, with its variants laser peening and ultrasonic peening, or cold spray. Shot peening is commonly used to induce compressive stresses in machine elements subject to fatigue. The large number of impacts involved in the process implies consequent computation time to obtain representative results. In this paper, we present a new approach to model shot peening by using a semi-analytical method that accounts for plasticity. The numerical efficiency of the code along with the use of a small representative area allows reduction in the computation time. It is also possible to observe, with a small number of impacts, the effect of several coverage rates. Thus the improving efficiency of the process with increasing covering rate can be observed as well as potential saturation effect when the covering rate is too high.