From what I saw a couple of weeks ago, the staff wasn't trained well to be efficient. As an example, when we went through the X-ray and metal detector station, the person who was supposed to view the X-ray scanner screen was checking passengers in wheelchairs. while she was doing that, the person running the metal detector stopped letting passengers through. Therefore, hand held baggage couldn't be x-rayed and many passengers wouldn't go through the metal detector because they wanted to stay with their hand held bags, phones etc. However, those passengers who didn't have to wait for handheld bags etc, who could have gone through the metal detector, got backed up as well.
Also, many passengers didn't show up at their assigned boarding times, trying to get on early and that jammed things up even more.