Its original terms of reference were comprehensive enough: they were to coordinate the drawing up of manufacturing processes and the fixing of piecework prices, to carry out time and motion studies of shop processes, to transfer work from overloaded to underloaded departments, and to keep in touch with advances in machine tool design. Additional duties came later, for instance the testing of new small tools and cutting steels and recommending the purchase of new and more efficient plant.

'P & R' scored an immediate success with a contract just secured for power plant for Australia at a price that appeared on the basis of the original estimates to involve a loss. It was decided that the new department should process the job down to the smallest detail with the result that on its completion a profit emerged. Since then the advance in manufacturing methods and specialization have made P & R with its records even more valuable, particularly in making available to individual departments the accumulated experience of all.

'Main production' department really arose from a proviso made by Bailey on his appointment—that a new department should be started to coordinate the production of equipment involved in composite or interdepartmental contracts. T. F. Lister, who had joined the Company in 1906 and had been concerned with production from the early days, was chosen as the first superintendent in 1921. In 1925 he left to join the Hackbridge Electric Construction Company (later following W. W. Hughes as chairman and managing director) and was succeeded by R. B. D. Lauder, who remained superintendent until 1940.

Today main production department is responsible for time-planning and coordinating the programmes on some 400 large composite contracts, ranging from steam and water power stations to mines, rolling mills and railway electrifications, and also on special contracts such as those for the Atomic Energy Research Committee. These are covered from the enquiry stage to installation on site, including coordination with the programmes of other manufacturers or contractors and, since the last war, of the Ministry of Supply and the nationalized industries, where major subcontracting is now involved. Continuous analytical work with appropriate action is necessary to cover an expanding field of constantly changing character.

A revolution in manufacturing methods began when fabrication by welding came up for consideration at the end of the war. Welding had long been used for repairing worn and damaged parts and for making sheet steel components such as small transformer tanks and switch boxes, but it was thought that many savings could be made by extending its use to larger products. In 1919 therefore a building that had been constructed for the fabrication of mines and paravanes was turned over chiefly to the welding of transformer tanks.