The FAA had essentially given Boeing the ability to certify its own aircraft after the manufacturer pressured the regulatory body to speed up the process to meet deadlines. In addition, the FAA defended its decision to do so by stating that this practice has been going on for decades and that it’s faster and cheaper this way.  The FAA claims that they oversee the process. However, the body only sees what a manufacturer puts in its report and nothing more. This is how Boeing was able to hide the issues that plagued the aircraft.