A United Kingdom consortium studying the future of the 'three-day car' says fundamental changes are needed at the paint shop stage of the assembly process.
The three-day period refers to the time it would take to order, build and deliver a car to a customer.
The 3DayCar Programme, an associated project of the International Car Distribution Programme and a consortium of auto industry groups, is halfway through a three-year study.
Geoff Williams, research manager for the program, thinks the three-day turnaround period can be delivered 'within the next decade.'
But he says some key changes to traditional vehicle production techniques will be needed.
Recent findings suggest the conventional automaker paint shop slows production, especially in terms of lead time and sequence reliability.
But new spaceframe technology could reduce dramatically the industry's reliance on traditional paint shops.
Recent cars that have benefited from spaceframes, which require minimal treatment in a paint shop, include the Fiat Multipla and Audi A2.
Spaceframes, which are structural frames with non-load-bearing panels, are constructed from aluminum extrusions, simple folded steel sheets or composite materials.
They offer lower tooling costs, model-change costs through the use of flexible platforms and increased production flexibility. The key organizations involved in the 3DayCar Programme are the Lean Enterprise Research Centre at Cardiff Business School in Wales, and the School of Management at Bath University in England.
Their efforts are backed by sponsorship from leading Tier 1 suppliers, six automakers, and the British government's Engineering and Physical Sciences Research Council and Department of Trade and Industry.
The paint shop survey, conducted by researchers at Bath University, focused on the six sponsoring automakers: Ford, Honda, Nissan, Peugeot, GM's Vauxhall unit and Volkswagen.
All these companies identify an order for a vehicle before the paint shop stage, which means the efficiency of their painting activity is vital if they are to move to a three-day system.
Among the plants surveyed, 40 percent of orders were held at any one time at the paint shop and painted body store stages, in relation to the average total number of bodies held throughout the assembly plant, from body framing to final inspection.
SPACEFRAMES SAVE TIME
Key requirements of the three-day car include minimal production lead time and the introduction of a reliable, water-based or powder paint system capable of delivering batch sizes of just one vehicle.
Current batch sizes in the industry average around 12 vehicles. Automakers using batch sizes of one vehicle are struggling to meet laws on paint shop emission levels.
Good, reliable surface finishes are harder to achieve with water- or powder-based paint systems than with traditional solvent-based systems, something that automakers switching to the more environmentally friendly systems have discovered recently.
Researchers on the 3DayCar Programme believe spaceframes offer a major opportunity to achieve the three-day target. Spaceframes would render conventional body and paint shops largely redundant.
Although 95 percent of global automotive production uses the welded steel monocoque as the conventional form of body construction, many automakers are diversifying their approach toward body construction.
Researchers on the 3DayCar Programme believe that with the use of spaceframes and solid-colored plastic panels, around 12 hours or more of production order lead time can be saved through the elimination of central body and paint shops.
The researchers also say it is feasible to produce a spaceframe and only identify it against a retail order at the beginning of the vehicle assembly line.
Drawbacks exist, however. Even though spaceframe constructions help automakers to plan batch sizes of one and theoretically allow any combination of model variants to be built to order, total output still needs to be significant to offer the economies of scale of the welded steel monocoque.
The typical spaceframe requires about one-third more components during body frame construction and requires higher levels of manual assembly, both of which affect costs.