When fitting contacts to connectors, the flexibility of the wires and the irregularity of the contact shapes have proved to be the greatest obstacles in developing automation. Within the framework of the present project, two methods for fitting irregular and flexible parts have been developed, both using industrial robots supported by vibrating tools. For theoretical analysis the irregular, flexible part is mathematically idealized. The tests are carried out with these idealized parts and crimp contacts. These tests proved that the vibration method is suitable for fitting irregular, flexible parts.