Petroski on Engineering: Checklists & Design

Dr. Atul Gawande is a surgeon at Boston's Brigham and Women's Hospital, where he specializes in the removal of cancerous endocrine glands. He is also a staff writer for The New Yorker, where he has published provocative articles on American healthcare. Some of these articles have dealt with topics that have also been the subject of his three books: Complications: A Surgeon's Notes on an Imperfect Science (2002), Better: A Surgeon's Notes on Performance (2007), and The Checklist Manifesto: How to Get Things Right (2009).

Although a medical doctor's reflections on surgery might seem to be remote from an engineer's concerns with design, some common features of the two topics are suggested just by the titles and subtitles of Gawande's books. Design, being an imperfect science -- if it can be considered a science at all -- is certainly subject to complications. Designers are always striving for a product that performs better than the last. And designers certainly want to get things right. But the insight and wisdom contained in Gawande's books go far deeper than the titles on their covers.

In fact, in his most recent book, the surgeon recounts looking to the realm of engineering for ideas that are transferable to the operating room so that the occurrence of complications and death there can be reduced from the staggering levels that persist in America today. For example, of the more than 50 million operations performed annually, about 150,000 result in death. That's over three times the number of deaths attributable to highway accidents in the US each year.

Gawande reports that research has determined that over half of the major complications and deaths that occur as a result of surgical operations are avoidable, for they are attributable to correctable mistakes, such as forgetting to give the patient an antibiotic prophylaxis before an incision is made, or failing to have a supply of the right type of blood at the ready should it be needed during an operation. It was Gawande's intention to reduce the 0.3 percent surgery failure rate by reducing the occurrence of unforced errors. It was this desire that led him to wonder how other professions achieve much better success in their specialty procedures.

When a new building was under construction to expand the capacity of his hospital, the erection of its steel skeleton made Gawande wonder how structural engineers achieved the high levels of success that they do. This in turn led him to look into the way that construction projects are carried out generally. He felt that there should be lessons to be learned from an industry in which the annual rate of failure (defined as partial or total collapse of an occupied building) was only 20 per 100 million, or 0.00002 percent.

What he learned was that a project manager relies heavily on the critical path method, in which all construction activities are clearly spelled out in a format that makes explicit how the work breaks down. There is also a schedule that shows the duration of each type of activity, as well as an indication of how the various activities depend upon each other. For example, the concrete for the fourth floor of an office building cannot be placed before that for the third floor is strong enough to support the formwork for the next higher floor. To Gawande, these kinds of considerations were effectively checklists, or formal statements of what had to be done in what order to assure the successful completion of a project.