Innovation: Rolls tests thrust on screen: Sophisticated computer-aided design will save millions on costly aero engine prototypes

ROLLS-ROYCE says it will cut a year off the time taken to create a new jet engine with a pounds 40m investment in computer systems which can design, build and prove the engine before a single piece of metal is cut.

Adopting electronic product definition will save the company millions of pounds in physical models built prior to full-scale testing, reducing time to market from four to three years and cutting costs by around 30 per cent.

Most manufacturing companies use computer-aided design systems in product development. But this is claimed as the first time that such complex products - the RB211 engine has 18,000 components - will be fully defined electronically without the need for physical models. Ford Motors has a technology programme with similar objectives, and other companies such as Shorts, which makes aero-engines in Belfast, and the diesel engine manufacturer Perkins Technology have taken steps along the way.

Rolls-Royce is spending pounds 14.1m this year on computer-aided design systems, with the balance of the investment being phased in by 2000. All this money will go to one company, Computervision, which has been working with Rolls-Royce on electronic product definition since 1989. The aero-engine manufacturer has been using Computervision equipment since 1979.

Phil Ruffles, Rolls-Royce Aerospace group director of engineering, said the contract was intended to 'improve the strategic alignment of our technology with our business'.

Rolls-Royce has already tested the technology by using it to dress its newest and most powerful engine, the Trent. This process, which involves adding the thousands of components such as fuel pipes, monitoring systems and cables that run around and connect to the jet engine core, traditionally involves working on physical models to make sure, for example, that there is space for each component.

Using a computer-based process called digital pre-assembly, Rolls-Royce reduced the time taken to perform this task by 12 weeks.

'It has long been possible to define a product electronically in terms of its geometry, but that is only one level of information. The Computervision system also knows the relationship between all the parts,' said Mark Holmes, Computervision's marketing communications manager.

The electronic model also has an advantage over the physical model in that it can be instantly updated as different design teams make their contributions. This means everyone is always working on the most up-to-date version. The software also manages all the engineering data (which may be mechanical, electrical or electronic data) so that various specialists can work on the project at the same time, rather than waiting for 'their turn' in a linear design process.

Roll-Royce will integrate its own test software - which, for example, performs stress analysis and aerodynamic testing of the designs - with the Computervision design software, allowing this work to be carried out concurrently as well.

These design systems also represent a step forward in terms of the intelligence of the model they produce. The system captures the logic of all the components, so that when it defines a cable it knows not only its physical structure but also what goes through it. If a designer tries to connect it wrongly, the system will be able to point this out.

'This makes an enormous difference to the quality of the product. Aero companies are extremely strict and rigorous in their design standards, but, historically, to reach them has meant a lot of checking and time,' Mr Holmes said.

David Lester, engineering systems strategy manager at Roll-Royce, said the new approach would change the company's relationships with its suppliers. 'The aim is to work more in parallel with our suppliers.' This will involve moving information around more effectively, to get suppliers working concurrently with Rolls- Royce's own teams in what is referred to as an 'extended enterprise'. As part of the contract, Computervision will set up a consultancy to help suppliers integrate their design and manufacturing systems with the Rolls-Royce system.

'There are always risks with designing a completely new engine,' Mr Lester said. 'This technology will cause it to be less traumatic.'

(Photographs omitted)