Performing an appendectomy, flying a 747, and building a skyscraper are deeply complex tasks that require specialists and the proper tools. Despite the deep knowledge and high-tech tools needed to get the job done safely, complications arise. What is one of the easiest ways to prevent accidents and keep such complex tasks running smoothly? It isn't more training and better equipment, according to surgeon Atul Gawande. It is something simple and often overlooked - the humble checklist.