An optimisation method based on an effective process model is presented. The calibrated and verified process model simulates peening on realistic components and provides a non-linear relationship between peening parameters and deflections. An optimal solution can be found by minimising the deviation of the computed deformed shape from the desired shape subject to certain constraints. This optimal solution of peening parameters can be directly used for practical operations. An optimisation example for forming a cylindrical shape on a 76x76x3 mm sample is provided. The experimental results demonstrate the applicability of the present optimisation method