Topography of the proposed NNBPN model to predict surface roughness and power consumption is shown in Fig. 4. It is feed forward back propagation network trained with Levenberg–Marquardt back propagation algorithm. Experimental data is used for training and testing the developed back propagation neural network model. The learning function is gradient descent algorithm with momentum weight and bias learning function. The number of hidden layers and neurons are determined through a trial and error method, in order to accommodate the converged error. The structure of the developed neural network is 4–9–6–2 (4 neurons in the input layer, 9 neurons in 1st hidden layer and 6 neurons in 2nd hidden layer and 2 neurons in the output layer). With a learning rate of 0.57 and a momentum term of 0.9, the network is trained for 10,000 iterations. Error between the desired and the actual outputs is less than 0.001 at the end of training process.