The paper presents the mathematical model of abrasive waterjet milling process. Based on analysis of existing models the authors realize a new mathematical model, considering some simplifying hypothesis. This model uses output data from model  and determines the advance speed, the consumption of the abrasive and the productivity of the process. To establish the productivity of the process and the advance speed we’ll use the “energy preservation” model. This model takes in account the material characteristics. The mathematical model has been solved numerical and the results have been interpreted.