Taming the industrial cuckoo ... CAD/CAM

Press, 4 February 1986, Page 29

Taming the industrial cuckoo ... CAD/CAM

By ALAN PIPES London “Observer”

After the British Government injected £24 million ($65 million) of aid in the early eighties to help first-time buyers of computer-aided design and computer-aided manufacture kits, 1985 was the year when the industry, known as CAD/ CAM, came a cropper. Last year will be one the industry would prefer to forget. Boston-based Computervision — the market leader since the late sixties, when it first put together an off-the-shelf computer and invented the turnkey system — reported staggering losses. Other United States companies, such as Megatek and Telesis, only months after opening British offices, packed their bags and went home. A respected British software house, Norrie Hill, called in the receivers, and even IBM spoke of a reduction in anticipated profits.

But the dark cloud has a bright side. A new realism is emerging in CAD/ CAM-land, and users are becoming increasingly assertive, confessing disappointment with the systems available. In spite of

the popular notion of CAD/CAM, it is not used to design products; at its best it is an indispensable tool for drafting after the design has been agreed. The electronics industry has cottoned .on to this most successfully; producing new chips would be impossible without CAD.

No one will admit failure or a wrong decision. After recommending that the company spends $700,000 or so on a system, the managers responsible will make sure it at least appears to work. The trouble is that the appreciation and application of CAD/CAM has always lagged far behind the development of the technology. Too much software is produced with little or no relation to demand, with vendors preferring to develop in width, not depth, so as to satisfy as many potential markets as they can.

The prestige of being seen to use high technology is a large factor in any organisation’s decision to invest in CAD; it is the industrial version of keeping ahead of the

Joneses. CAD’s marketing potential was vitally important to the London consultancy PA Design, when it decided to invest £105,000 ($290,000) in a system last year. The product engineer, Ed Matthews, put it this way: “If we can attract a few big jobs by having CAD, then the system is paid for. If it works, too, and gives the

company a competitive edge, then that’s a bonus.”

So what are the hidden costs of CAD? Training is one. CAD systems, in spite of what the salesmen say, are not easy to come to grips with. The problem is compounded by the changes relentlessly taking place in the technology. The socalled user interface is forever “improving.”

The latest models have you selecting commands from icons (tiny pictures) and menus that pop-up all over the screen. You can run several jobs at a time on overlapping “windows.” If you had an untidy desk, now you can have ap untidy screen. CAD systems have yet to move from the domain of the resident enthusiast

who will work round the clock to discover every arcane trick buried in the system’s command structure. More importantly, though, the systems on the market do not come up with the goods. It is a popular misconception that CAD systems are used to design products. (Two 12-year-olds were

overheard on the train returning from a visit to a motor show: “Do you know why all cars look the same?” said one. “Because they’re all designed using CAD.”) For the vast majority of firms which use CAD, the “D” stands for drafting — and that is as far as it goes.

All kinds of wild productivity gains have been quoted for computeraided drafting, but the usual rule of thumb is in multiples of three — a third of the staff can generate three times as much work in a third of the time. But this depends on the kind of work. If a firm is producing repetitive drawings using lots of standard symbols and subassemblies that can be called up from the computer’s library, or is continually updating old drawings, then these figures could be true. For one-offs, the computer is probably slower than the drawing board.

For truly integrated manufacture, a fundamental barrier remains to be overcome. There needs to be a complete and unambiguous representa-

tion of the product being designed already in exist- “ ence and accessible at the « heart of the CAD/CAM system. The only type of system that can meet this requirement is called a solids modeller. Solids modellers are slow, expensive on computer power and cumbersome to use. They cannot yet handle the doublecurved “fair” surfaces found in aeroplanes, car bodies and telephone handsets. And that is not all. Researchers have still to find away of attaching "tolerance” Information to the part’s geometry.

Tolerances are vital to production engineering J and have crucial cost im- ■■ plications on manufacture , — for example, a 0.02 mm tolerance on a IOOmmT dimension is 20 times more expensive to comply * with on a horizontal borerthan on a lathe.

Finally, there is the.un-T glamorous sbject of stand- ■ ards. Most -users would 2 like to .communicate de--sign data between dlf-" ferent makes of system. IGES (initial graphics exchange standard) can - transmit 85 per cent of a drawing from one vendor’s system to another.