Different values for each design variable are selected to cover a wide range of cutting conditions. The selected design variables viz. cutting speed, feed rate, depth of cut and rake angle have no interaction with each other and have been considered as independent variables by several researchers [1-4]. Table shows the levels of factors used in the simulations. These ranges are based on various design of experiment (DOE) factor levels used in practice and found in literature [2, 10, 19-21]. Having excess width in the range of these parameters can lead to poor response quality  and therefore may not produce the results which would establish the optimum conditions. The response variables for this study are cutting force and temperature. According to the array selector given by Stephanie Fraley et al. , if there are 4 control variables and 5 levels of each in the DOE, as specified in the previous section, the Taguchi L25(54) array is to be utilized. This array is tabulated in Table .
Table DOE Fctors and Level values for simulation with AISI 1045 steel.