The Checklist Manifesto by Atul Gawande

have to resolve it.
    There’s yet another program, called ProjectCenter, that allows anyone who has found a problem—even a frontline worker—to e-mail all the relevant parties, track progress, and make sure a check is added to the schedule to confirm that everyone has talked and resolved the matter. When we were back at the McNamara/Salvia offices, Bernie Rouillard showed me one such e-mail he’d gotten that week. A worker had attached a digital photo of a twelve-foot steel I beam he was bolting in. It hadn’t lined up properly and only two of the four bolts could fit. Was that all right, the worker wanted to know? No, Rouillard wrote back. They worked out a solution together: to weld the beam into place. The e-mail was also automatically sent to the main contractor and anyone else who might potentially be required to sign off. Each party was given three days to confirm that the proposed solution was okay. And everyone needed to confirm they’d communicated, since the time taken for even this small fix could change the entire sequence in which other things needed to be done.
    Joe Salvia had earlier told me that the major advance in the science of construction over the last few decades has been the perfection of tracking and communication. But only now did I understand what he meant.
    The building world’s willingness to apply its strategies to difficulties of any size and seriousness is striking. Salvia’s partner, RobertMcNamara, for instance, was one of the structural engineers for the Citicorp (now Citigroup) building in midtown Manhattan, with its iconic slanted rooftop. It was planned to rise more than nine hundred feet on four nine-story-tall stiltlike columns placed not at the building’s corners but at the center of each side and steadied by giant, hidden chevron-shaped braces designed by William LeMessurier, the project’s lead structural engineer. The visual effect was arresting. The colossal structure would look like it was almost floating above Fifty-third Street. But wind-tunnel testing of a model revealed that the skyscraper stood so high above the surrounding buildings in midtown that it was subject to wind streams and turbulence with forces familiar only to airplane designers, not to structural engineers. The acceptable amount of sway for the building was unknown.
    So what did they do? They did not scrap the building or shrink it to a less ambitious size. Instead, McNamara proposed a novel solution called a “tuned mass damper.” They could, he suggested, suspend an immense four-hundred-ton concrete block from huge springs in the building’s crown on the fifty-ninth floor, so that when wind pitched the building one way, the block would swing the other way and steady it.
    The solution was brilliant and elegant. The engineers did some wind-tunnel testing with a small model of the design, and the results were highly reassuring. Nonetheless, some chance of error and unpredictability always remains in projects of this complexity. So the builders reduced their margin of error the best way they knew how—by taking a final moment to make sure that everyone talked it through as a group. The building owner met with the architect, someone from the city buildings department, the structural engineers, and others. They reviewed theidea and all the calculations behind it. They confirmed that every concern they could think of had been addressed. Then they signed off on the plan, and the skyscraper was built.
    It is unnerving to think that we allow buildings this difficult to design and construct to go up in the midst of our major cities, with thousands of people inside and tens of thousands more living and working nearby. Doing so seems risky and unwise. But we allow it based on trust in the ability of the experts to manage the complexities. They in turn know better than to rely on their individual abilities to get everything right. They trust instead in one set of checklists to make sure that simple steps are