Born in a Storm

By Doug Bartholomew  |  Posted 02-05-2007 Print Email


Born in a Storm

Airbus' 2006 nightmare with PLM can actually be traced back to the giant company's difficult birthing process in 2001. "This issue dates back to the historical structure of Airbus," recalls former Airbus financial executive Massey. A loose consortium of French, German, British and Spanish companies formally spun out Airbus in 2001 at the same time the A380 program was being launched.

Massey well remembers the infighting among the partners over jobs, and over which country would get the bulk of the mammoth aircraft's production work. Some executives, in fact, expressed the feeling that, as Massey puts it, "We shouldn't be launching this aircraft put together by four different nations." Such disputes can have a downside, resulting in a level of distrust or, at best, erratic coordination. "Because there was an awful lot of debate about the way to create this single-company structure, the A380 was held hostage to that," he says.

For example, the Germans were adamant that the entire aircraft not be built in France, where Airbus was headquartered. Ultimately, work on the A380 was carved up among the four players, so that at its founding in 2001, Airbus had offices and factories at 16 sites spread across four countries and employing 41,000 people. Each country had a level of independence to go its own way when it came to systems and technology, Massey points out.

This lack of strict uniformity of processes and technologies laid the seeds for what was later to grow into an entangled vine of trouble for Airbus. "The systems had been set up under the old structure," Massey says. "No one was watching who was using what versions of Catia. It may be a systems issue, but as much as anything, it's a management issue."

Airbus' lax enforcement of a single lingua franca for design was at the heart of the A380's later problems. While there are many ways that different CAD systems, and even different editions of the same CAD programs, can trip up a product's design, those ways become multiplied with the complexity of the end product and the increased number of suppliers creating parts or components for its manufacture.

By contrast, Boeing management is taking no such chances. Well before Airbus' problem became public, the U.S. aerospace manufacturer had put into place a rigorous set of requirements to ensure that the same edition of Catia is used by everyone connected with the shaping of the Dreamliner.

At least one Airbus design manager was well aware of the potential for a CAD incompatibility disaster. Martin Horwood, lead engineer for CAD capability development at Airbus U.K., co-authored an article titled "CAD Data Quality" in the May-June 2005 issue of Engineering Designer magazine in which he warned, "With data arriving into the digital mock-up from a globally dispersed design community, including industrial partners, suppliers and subcontractors, it is imperative that the CAD data is of the right quality. Failure … will cause the digital mock-up to be inaccurate and not fulfill its task, leading to expensive reworks in real life."

And fail it did. With its German designers creating wiring bundles to fit inside one set of spaces in the A380's fuselage using Catia V4, and the French designers having created the fuselage wiring spaces using the more modern Catia V5, the actual wiring bundles were unable to fit.

Says Peter Schmitt, vice president of marketing and communications at Dassault Systèmes of America, "The 6 billion [dollar] loss at Airbus was the result of a fairly simple problem that could have been fixed with a fairly low investment." Schmitt didn't offer an estimate of how much it would have cost or how long it would have taken for Airbus to upgrade the German unit to Catia V5. But his message was clear: Companies using PLM should make sure they are using the same software package and version of that software. "Manufacturers using PLM," Schmitt adds, "should make sure everybody is working with the same set of data."

Although Airbus has remained mum on exactly why the German designers used an older CAD package, most observers believe the reason was simple Eurodollars and Eurocents.

The cost to train the engineers in Catia V5 may have been the sticking point for Airbus management that led to the A380's multibillion-euro design flaw. That's the view of an executive at a firm that trains Airbus' suppliers to use Catia. "Airbus made the decision not to migrate Germany to Catia V5 because it would have meant a complete retraining," says Geoff Haines, managing director of Cenit Ltd. in Oxford, England. "They decided not to do it for budgetary reasons."

So great is the chasm between the two versions that someone schooled in Catia V4 trying to get up on V5 is similar to a motorist learning to fly an airplane. It takes six months to a year before they become fully proficient, Haines says. "It would be like starting from scratch," he adds.

Those unfamiliar with CAD software may be wondering just how two versions of the same software package could be incompatible, or for that matter, require such extensive retraining. The reason is the two software editions differ in their basic treatment of drawings, so the way digital models are created is different.

Both systems are able to represent objects in 3D, but that's where the similarities end. Engineers using Catia V4 must use a manual process to create the geometry of a model. To create a hole inside an object, for example, the system requires them to subtract a cylinder from the space to define where the hole should exist. By contrast, the product designer using Catia V5 simply feeds in a set of engineering instructions—in effect, describing the location and dimensions of the hole—and the geometry is automatically created. "V5 is higher-level, more intuitive," says Doug Cheney, product manager for CAD interoperability quality at ITI TranscenData, a developer of CAD translation software. "With the older system, the engineer figures out the geometry; with the new one, the system finds the best geometric solution."

Airbus engineers ran afoul of this basic difference when creating the miles of wiring to be inserted inside the A380 fuselage. The engineers' "notes"—appendices that describe details of models such as curves—sometimes are not replicated in the translation between Catia V4 and V5, says David Prawel, president of Longview Advisors, a Loveland, Colo.-based consulting firm specializing in 3D software issues for manufacturing. In other words, key notes required to duplicate a 3D model showing electrical wires as they twist and bend through the aircraft may fail to reappear in full and accurate detail when a design file in one system is converted to a file in the other.

For example, something basic such as the tolerance level of a metal part, noted by an engineer in the appendix to a 3D drawing, may be left out when the model is converted from one system to another. The result can be that the manufacturer—or a supplier—may produce the part to the wrong tolerance.

In addition, units of measurement, when carried over from one CAD system to another, can create havoc for designers, says Brian Barsamian, president of V5 Engineering, a Newport Beach, Calif., firm. Barsamian trains engineers—including many designers at Boeing—to use Catia V5. "There was a complete rewrite of the code from V4 to V5," he says. "You have to be careful to set parameters defining whether you are exporting metric units or English units; otherwise, a 1 millimeter part can become 25.4 millimeters, because it sees 1 millimeter as 1 inch."

Still, most CAD vendors offer their customers a smooth path to convert their data from an earlier version to a new one, according to Prawel. "Every vendor does a good job of backward compatibility except Dassault," he says. "Why some of the biggest aerospace companies and automotive manufacturers in the world didn't force them to do a better job of backward compatibility is a mystery to me. Now Airbus is paying the price." To solve this problem, Prawel says many Dassault customers have decided to start from scratch to re-create, or remaster, the data in all their existing models in Catia V5 because of its lack of smooth interoperability with the earlier version.

Dassault owns up to the programs' dissimilarities, and the potential minefield they pose for manufacturers adopting PLM midway into an upgrade cycle, or just trying to get the pair to coexist. "If in one organization they are using both versions in parallel and have to synchronize data on a constant basis, that is what causes problems," Schmitt says. However, he says using the two versions does not necessarily spell trouble. Schmitt notes that Dassault has several customers that have successfully used Catia V4 and V5 concurrently on long-term projects.

Another area where Airbus tripped up was in the 3D digital mock-up of the A380. Both companies, Airbus and Boeing, use a digital mock-up as a final design step. Boeing is meticulous in its 3D mock-up process, having had extensive experience in using a virtual mock-up for its earlier 777 jet and in later iterations of its top-selling 737 plane.

The 3D digital mock-up of the A380, however, was done well behind schedule, with a new design team that was under pressure to get it completed. "The problem is the fact that the 3D digital mock-up, which facilitates the design of the electrical harnesses' installation, was implemented late, and that the people working on it were in their learning curve," states an Oct. 3, 2006, Airbus press release. The company signed its first major contract for mock-up software just this past year.



 

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