A method of producing an assembly tool (60) for assembling an assembly (6), the method comprising: providing at least a portion of a jig frame (62); fixing support plates (65) to the jig frame (62); machining the one or more support plates (65) such that a surface of each of the support plates (65) lies in a common plane (130); positioning the jig frame (62) such that the machined surfaces of the support plates (65) contact with a supporting surface (138); fixing pickup device mounting plates (140a, 140b) to the jig frame (62); machining, with respect to the supporting surface (138), the pickup device mounting plates (140a, 140b) such that a surface of each mounting plate (140a, 40b) has a respective predetermined position and orientation with respect to the supporting surface (138); and fixing, to the machined surfaces of the mounting plates (140a, 140b), a respective pickup device (66-72).

Disclosed is a method of producing a machining fixture for fixedly holding a workpiece during machining of that workpiece. The method comprises: providing an initial machining fixture comprising a plurality of receiving elements for receiving the workpiece to be machined; determining a datum, the datum being dependent upon the relative positions of the receiving elements; determining positions and orientations of one or more reference surfaces with respect to the datum; measuring the surface of the initial machining fixture with respect to the datum; and, thereafter, controlling machining apparatus with respect to the datum to machine the initial machining fixture to form the one or more reference surfaces, thereby producing the machining fixture.

An assembly process for assembling at least part of an aircraft airframe, the assembly process comprising: providing a first assembly including a first part of the airframe and a first reference structure attached thereto; providing a second assembly including a second part of the aircraft airframe and a second reference structure attached thereto; receiving, by a first receptacle, the first reference structure; receiving, by a second receptacle, the second reference structure; moving, by an actuation device, the receptacles into a predetermined configuration, thereby moving the first part of the aircraft airframe and the second part of the aircraft airframe into a predetermined configuration; and performing an assembly operation on the airframe parts to fixedly attach together the first part of the aircraft airframe and the second part of the aircraft airframe, thereby producing the part of the aircraft airframe.

Automated fixture layout is approached in two distinct stages. First, the spatial locations of clamping points on the work piece are determined to ensure immobility of the fixtured part under any infinitesimal perturbation. Second, spatial locations are matched against a user-specified library of reconfigurable clamps to synthesize a valid fixture layout or configuration that includes clamps that are accessible and collision free. The spatial locations matching during the second stage can be the same spatial locations chosen in the first stage to ensure immobility, or a different set of spatial locations.