If you recall, McDonald's used to have heated transfer bins where they kept burgers already made. The holding time was for 8 minutes(standard) before being tossed and usually allowed just enough time for the cheese to melt..combined with fresh meat made for a ok burger, fast and at a fair price. Waste was high if production was not controlled properly. Burgers sitting in the transfer bin too long were also junk.As the menu expanded and more products were added with lettuce and tomato etc the old system was dumped.