A method of partitioning involves a predetermined layout of parts that are to be cut out from a sheet of flexible material by moving at least one cutter tool along two directions in at least two distinct and determined cutting windows along which the material is advanced in succession. Starting from a predetermined layout of the parts in the material, the method comprises: automatically creating mutually distinct groups of parts by allocating each part to a single group of parts as a function of its geometrical position, each group of parts being associated, for cutting out, with a single cutter tool and with a single cutting window; and applying spacings between the various groups of parts.