Initial production of the A380 was troubled by delays attributed to the of wiring in each aircraft. Airbus cited as underlying causes the complexity of the cabin wiring (98,000 wires and 40,000 connectors), its concurrent design and production, the high degree of customisation for each airline, and failures of configuration management and change control. The German and Spanish Airbus facilities continued to use CATIA version 4, while British and French sites migrated to version 5. This caused overall configuration management problems, at least in part because wire harnesses manufactured using aluminium rather than copper conductors necessitated special design rules including non-standard dimensions and bend radii; these were not easily transferred between versions of the software.