The offshoring risk
Some degree of outsourcing in other countries – offshoring – is an inevitable aspect of manufacturing a complex product like an airplane because some expertise exists only in foreign countries. For example, the capacity to manufacture aircraft cobalt lithium-ion batteries lies outside the US Boeing had no choice but to have the batteries made in another country.[10] More than 30 percent of the 787's components came from overseas. By contrast, just 5 percent of the parts of the 747, were foreign-made.[11]
While there is nothing in principle wrong with necessary offshoring, the cultural and language differences and the physical distances involved in a lengthy supply chain create additional risks. Mitigating them requires substantial and continuing communications with the suppliers and on-site involvement, thereby generating additional cost. Boeing didn't plan for such hands-on involvement, and so incurred additional risk that materialized.