Modern Software Problems - The Technical and Social History of Software Engineering - page 368

Finally, as a result of class-action lawsuits, Sony paid damages to affected cus-
tomers. This is not a good way for Sony to do business in a world with sophistic-
ated clients who have instant access to the web.
2006: Airbus A380 Wiring Problem
The Airbus A380 is a giant passenger plane designed to compete with Boeing 747s
on long-distance routes. The Airbus was delayed by more than a year due to soft-
ware problems related to the onboard wiring harness.
Modern aircraft, including the A380, are highly computerized, and most con-
trols and navigation are handled with software assistance. As a result, there are
miles of electrical wires and thousands of connectors. The A380 has about 550
kilometers, or 330 miles, of onboard wiring.
The CAD design software for the A380 was a commercial package. The Ger-
man and Spanish design teams used version 4 of the CAD package, while the Brit-
ish and French design teams used version 5. This caused configuration control
problems.
Worse, the design team had the CAD package set up for copper wires, but
aluminum wires were used in the wiring harness for the wings. The difference
between aluminum and copper caused other problems because the diameter of the
wires was not the same, nor was elasticity the same. It is harder to bend aluminum
wires than copper wires.
Lessons learned: The primary lesson learned from this problem is that multiple
design teams in multiple countries should all use the same versions of CAD pack-
ages and any other complex technical tools. A second lesson is that when you use
software to model physical equipment such as wire diameters and elasticity, be
sure to have the software exactly match the physical components.
Problem avoidance: The differences between copper and aluminum wiring could
easily have been found by design and code inspections prior to final approval on
the design. They might also have been found by requirements modeling. This is
not a kind of problem where code static analysis might have found the problem,
but perhaps a text static analysis tool could have identified it before serious harm
was done. The damage was done by using the wrong settings on a CAD tool, so
pair programming would not have found the issue.
The use of testing for this problem was not really in the mix because the prob-
lem manifested itself in physical problems noted during construction of the plane.