 Boeing is inspecting components like fuselages before they are delivered in an effort to reduce product defects entering its factories and has slowed production to shore up quality. One of the big changes Boeing talked about during this media tour of the 737 MAX production line was the ability for employees to stop the work, stop the line if they see a problem. In fact, on build day five, there's a plane-sized gap in the line because the line was stopped to fix a problem.