Concept: Lithium-ion batteries are great tech.
Design: Boeing outsourced the electrical system design work to Thales, and the first production airliner designed around lithium-ion batteries seemed like a great idea until they started catching fire.
Execution: Relying heavily on sub-contractors to build big chunks of the 787 was a great idea to save money, until the subs couldn't maintain the pace Boeing wanted for the price Boeing was willing to pay. So Boeing bought the South Carolina facility.
And Boeing keeps insisting on learning the hard way. Last year the FAA halted deliveries of the 787 for a few months due to quality issues.