Thirty minutes before new parts arrive at BMW's Mini plant at Oxford a detailed plan for the supply chain's internal operation is set in action.
Working to a tight schedule is part of taking the costs out of building cars and planning everything down to the last screw is essential.
Parts have a colour code and depending on the colour they will go into the warehouse for later direct delivery to the production line or take their place in the line for just-intime delivery.
"This is the management of the inventory in the earliest phase when it arrives at the plant," said Ralf Hattler, director of logistics, IT and structure planning.
About 2,100 part types move through the warehouse, which covers 22,000 sq metres, to the Mini assembly line for just-in-time use.
The parts come in from various manufacturing centres in Europe but they are kept in stock for only a few days before they are used. All the parts in the warehouse are for general use and exclude specific items requested by the customer whose car is about to be built to their specifications.
Mini has about 200 suppliers and 119 of them are based in the UK giving them 60 per cent of the parts business for the plant.
The main components come from within the UK. Pressings are done at Swindon at BMW's own pressings plant and subassembly work is due to be moved to Swindon in the future.
Some pressing are done at Land Rover's site in Lode Lane, Solihull, on a £60 million press acquired by BMW before it sold the plant to Ford.
The Mini cockpit is built by Redditch firm Intier and within six hours of arrival they may be called-off for the production line.
During a three-day period the warehouse operates to receive parts round-the-clock and the other four days are flexible to accommodate vehicles bringing in stock from a distance.
Commercial vehicles carrying the parts are not permitted to be driven at weekends in Germany.
The handling of the stock is complex and also crucial to the smooth flow of car production which sees petrol and diesel engine Minis and the variant soft-top moving along the production line with left-hand drive models for the US, Europe and other worldwide markets.
These ordered cars are frequently accompanied by special request demands from the owners who want their cars to have an individuality with the available extras.
Much of this activity is in the cockpit area and involves radios, CD players, satellite navigation, steering wheels and steering columns, seats, air conditioning and colours.
Externally it is mainly trim and lights.
Delivery to the production line has achieved a rightfirst-time figure of 99.9 per cent, a demonstration of accurate ordering and handling of stock.
These operations are carried out by external services partner Rudolf Hellmann, but responsibility for the whole process still rests with Mr Hattler and his team.
T h e R u d o l f Hellmann company looks after receiving of the parts, inventory levels and delivery of the components to the line as well as the operational management of the warehouse.
A good relationship with suppliers is essential and as soon as a new supplier is selected planning and cooperation gets underway. BMW's central planning operation in Munich is very much involved at this stage.
Quantities of parts are discussed and how many times there will be a call-off for components and the number of deliveries to be made.
"The companies chosen must have capabilities and have a high knowledge of engineering and quality," said Ralf Hattler, director of logistics, IT and structure planning. "The logistics performance is identified and developed before the start of a new product. We measure and monitor
"This is an intensive period and we also have to maintain the supply chain quality and for this function we are in close co-operation with the suppliers so that when they start their relationship with us everything is in place.
"During the normal operation process we are in daily contact with suppliers to calloff parts and to ensure the
correct materials are coming forward. We also have an internet operation and they can get into our system.
"We are able to give them an early forecast of production on a monthly basis and then refine it to a weekly production forecast so that suppliers know exactly what is required."
Building one model type should mean just-in-time is less complex but that is not the case when cars are not built in batches and each car has the mark of the individual buyer waiting to take delivery.
Mr Hattler said that because of the large number of possible specifications only one in 50,000 cars would be the same. The plant builds the Mini One, Mini Cooper, Cooper S and convertible variants and that brings with it different parts.
"It is hugely complex and each day we have more than 50 to 60 technical changes - we are continuously improving our cars," he said.
In 2004, a total of 189,492 Minis were built and Mr Hattler said the plant will at least match that total and perhaps produce more. To help the plant cope with increased production it is investing £100 million in a body-shell production extension as well as the paintshop and final assembly.
Another continuous challenge is to produce the car the customer wants at the right time and that is one of the reasons for operating a justin-time system. Customers have up to eight days before building starts on their car to finalise the extras they may require on the vehicle.
Suppliers, to all manufacturers, are working under constant costs down demands.
Mr Hattler said: "We have internal percentage targets which we must achieve. It does not make sense to keep stock on our site and the suppliers' sites. We work on a continuing improvement process between both sites to make the supply route effective. It is futile for the supplier to send a lorry every day. If it is coming from Spain or travelling some other long distance it may be halffull and that is putting up the transport costs."
Production workers at the plant total around 3,700 from a payroll of 4,500.
Production is based on three shifts covering day, night and weekend work.