1. A method for producing a system, the method comprising: providing a workpiece comprising a plurality of attachment features for attaching the workpiece to a machining fixture; determining a datum, the datum being dependent upon relative positions of the attachment features; measuring a surface of the workpiece with respect to the datum; providing the machining fixture; attaching, using the attachment features, the workpiece to the machining fixture; providing a digital model specifying a component of the system, the digital model including the attachment features; using the measurements of the workpiece surface and the digital model, controlling the machining apparatus with respect to the datum to machine the workpiece attached to the machining fixture so as to produce the component as specified by the digital model; removing the component from the machining fixture; providing an assembly tool; attaching, using the attachment features, the component to the assembly tool; and performing an assembly operation on the component, thereby producing the system.