Whistleblowers say the time and expense of manufacturing new parts led to pressure to use "nonconforming" parts on airplanes instead.
https://www.king5.com/mobile/article/tech/science/aerospace/boeing/boeing-whistleblowers-come-forward-ceo-senate-testimony/281-b559a57b-b21d-4463-b2a1-e4a066d99d4b