There is disclosed a method of estimating a precursor shape (44, 45) for a part (2) suitable for manufacture via a process selected from a plurality of manufacturing processes. The method includes: generating a convergence line (20) within the confines of a final part shape (1); providing an array (18) of spaced-apart forming shape points (19) around the final part shape (1); converging said points (19) towards the convergence line (20) using a force-energy-balance technique via a movement algorithm; and applying a smoothing algorithm to the converged points (19) to create an estimated precursor shape (44, 45). The algorithms include coefficients specific to a predetermined one of said manufacturing processes.