The metals used in vehicle manufacture have first of all to be cast, forged, pressed or otherwise processed. Castings and forgings have to be machined before they are ready for assembly into the completed vehicle, and the engineering work involved is an extremely important part of the process of manufacture. As the scale of output of any standardized product grows, costs can be reduced by altering techniques in two main ways. First and most important increasing mechanization becomes worthwhile. One step that can be taken is to fit standard engineering machines with devices to make their operations more automatic. The second way in which the technique of production is altered as the scale of output changes is that flow production methods supersede batch production methods. The Renault experience, however, is that the standardization of the special machine elements has allowed considerably increased production in their workshops without a proportionate increase in maintenance staff.