Fast track and fault free

Posted on 12 Aug 2008 by The Manufacturer

‘Design for manufacture’ is more than just a phrase: it’s essential to competitiveness. Ruari McCallion finds out how the design process has matured

Once upon a time, a designer was someone with a magic marker in one hand and a pensive expression on the face. He or she – usually he, in manufacturing – would come up with a wonderful-looking concept, for a car or whatever, and hand it over to an engineer who would allow a soft sigh to escape his lips and then set about making the idea a practical proposition. It may not end up as eye catching as the original rendering – and the designer may have shed a small tear about that – but it could be built and sold, profitably. The process of designers weaving impossible but attractive dreams corrected by engineers who erred on the side of earthiness and practicality is such a waste of time. But it’s difficult to overcome.

“The silo mentality is still quite strong,” said Gus Debarets, chairman of design company Alloy, which is based in Farnham, Surrey. “There’s still the sense that design should focus on the market, while engineering picks the ideas up and makes them work.” That is so 1990s. Companies that are responsive and agile have the various disciplines working together. The lines between design and engineering should be so blurred that the naked eye can barely discern them. While Peter Horbury, head of design at Ford, indignantly rejects any suggestion that he gets involved with the ‘dirty fingernail stuff’ (and laughs as he does), he has been a driving force in overcoming the silo mentality. He worked with Volvo from 1974 and was a pioneer of virtual reality (VR) design in the 1980s. Volvo California worked with software company Alias to develop film VR technology for the automotive industry. The location and the need were serendipitous: it was the right time and place.

“Sweden has a small population and doesn’t see technology as a threat to employment,” he said. The facility in Sweden rapidly became the most advanced design studio in the auto industry. Bringing it to Detroit in 2004 was a bit more of a challenge, as he was entering a longer-established industry with traditions of demarcation and craft-based departmentalisation. But the need was there and recognised by the relevant authorities. “Technology is vital to Ford’s future,” he said. “Tools like VR enable design iterations to
be completed quickly. With shorter lifecycles and pressure to bring products to market quickly, the traditional paper and clay approach, with ideas taking weeks to be realised, simply isn’t up to it.”

Drawings made using CAD programs are translated directly to online modelling systems, like Bunkspeed, in Ford’s case. It allows the studio to see what cars will look like, how light reflects on the body and the effect of different colours. Clay comes later and involves fewer models. Everything under the outer layer is incorporated into the body shape, so it will become apparent very quickly if components like suspension turrets are going to stick out of impossibly smooth lines. Before the idea gets out of the studio, a realistic and practicable vehicle is much more than halfway to production. The experience of Ultra- Motive in its design of the RenaultSport Clio V6, which was brought from show concept to finished article in just 15 months, gave some idea of what manufacturing-oriented design can achieve. But design for manufacture isn’t just about large scale projects for major global companies.

BK Tooling, of Bishop’s Stortford, Hertfordshire, employs just a handful of people making very high quality plastic mould tools and pressure die-cast tools. Being based in the UK gives an advantage in rapid turnaround and close customer liaison, but its main USP is its ability to deliver to very high standards. It makes the tools for Aquapac, a waterproof protection system for mobile phones, cameras and other sensitive equipment. The tolerances are remarkable – 10 microns compared with the CAD drawings, for example. Bob Tunks, the owner, believes in working closely with customers from the earliest stages.

“I much prefer to be in there at the start and understand how the product will be made, even tell them how the plastic will flow,” he said. Understanding material performance leads to better design of better products. But it doesn’t end there.
Derek Hall, of the West Midlands Manufacturing Measurement Centre (WMMMC) at Warwick University, is an evangelist of measurement as a core element in design for manufacture.

“We get involved from concept to manufacture, throughout product life,” he said. “From pre-prototyping to planning for manufacture, we promote the concept of measurement. Dimensional input and accuracies affect both final production and final product cost. Over-specification, for example, can cost a fortune. We worked with BK Tooling, who approached us to assist them in measuring some componentry they were making. The drawings themselves required tolerances that were very difficult for them to achieve and which were generating high scrap rates. As a disinterested third party, we went to the customer with a series of questions and, with their agreement, were able to amend the design to make them achievable. We helped to achieve fit-for-purpose tolerances, which led to better products at better prices.” WMMMC has run a series of ‘design for designers’ courses, which are essentially about communicating accurate understanding of tolerances.

Atlas Packaging’s in-house design team works with customers to enable them to optimise the appearance of the boxes they produce, and to ensure they get the optimum use of materials – with benefits on waste and cost. VT Shipbuilding in Portsmouth worked with the Royal Navy to improve the design of the Type 45 destroyers, and to incorporate modifications to reduce production time. If every boat was to have taken the same time to build as this one, the order would probably have been curtailed. The lessons learned have been applied to subsequent vessels, which have taken less time to build, thus saving money. According to Graham Cockman, the technical director, the key is to speak to suppliers even before selection, in order to ensure all the required information is available. The information is vital as design is all computer-based; without the appropriate data for engines, weapons systems and everything else that has to be housed inside the hull, it would be nearly impossible to generate accurate 3D models. VT advises suppliers like Rolls-Royce and Cummins what the capability requirements are for, say, generators and switchboards. They undertake the specific design and VT integrates them and ensures they fit within the skin.

Design software varies from the complicated, like ProEngineer and SolidWorks, to Acrobat 3D, which is a pdf-style design tool. What 3D CAD does is deliver clear information to the designer, the shopfloor and customers. They help to avoid pitfalls before they arise – not only internal components not fitting, but also things like heat build-up and stress in action – before the first prototype is built. Clearly, eliminating the errors before production saves huge amounts of time and money. BAE Systems Submarine Solutions, in Barrow-in-Furness, uses CAD and CAE programs which are so accurate that pipes and flanges can have holes drilled and the units trimmed before they are installed in the crowded submarine hull. The Caparo Innovation Centre, a joint venture with Wolverhampton University, helps inventors and innovative SMEs to develop ideas from concept to producable and marketable products. Covpress, in Coventry, is making a virtue of brainstorming with customers to reduce costs through changing designs and helping to improve processes. It may be redesigning a component to remove a step from the process, which saves time and work. A number of companies look at the materials: does a component need to be made of metal, which has to be machined, or will a high-strength plastic, which can be moulded, do the job at least as well – or even better?

“It’s amazing how many downstream problems disappear if issues are engaged with upfront,” said Debarets. “If design is creating the 3D data, why isn’t it also responsible for engineering data? If you make the designers effectively buyers, responsible for controlling cost, size, the number of processes and the BoM (bills of materials), they will sort the problems out. If they don’t think of themselves that way, they’ll delegate responsibility. If you’re designing ribs and bosses, for example, and when the design is delivered the engineer says ‘sorry, you’re using the wrong screws’, you’re the victim of stupidity.” The idea isn’t a huge leap; the one that is a reach is the concept that kids 12 months out of college are generating data that’s used to cut cavities at factories in China. Even if the production facility isn’t 6,000 miles away, it makes sense to engage design with engineering to make more marketable products more effectively and more quickly. The line between the two shouldn’t exist at all any more.