Summary: To Engineer is Human

This book has its origins in the basic question: What is engineering? It sets forth the premise that understanding failure is essential to understanding and achieving success in engineering. Fundamentally, engineering is figuring out how things work, solving problems, and finding practical uses and ways of doing things that have not been done before. Successful engineers properly anticipate how things can fail, and design accordingly. Case studies of past failures thus provide invaluable information for the design of future successes.

Conversely, designs based on the extrapolation of successful experience alone can lead to failure, because latent design features that were not important in earlier systems can become overlooked design flaws that dominate the behavior of more complex systems that evolve over time. This paradox is explored in To Engineer Is Human in the context of historical case studies, which provide hard data to test the hypotheses put forward. Among the historical data points are the repeated and recurrent failures of suspension bridges, which from the 1850s through the 1930s evolved from John Roebling’s enormous successes—culminating in the Brooklyn Bridge—to structures that oscillated in the wind and, in the case of the Tacoma Narrows Bridge, twisted itself apart and collapsed in 1940. Lessons learned from these cases and others are generalized to apply across a broad spectrum of engineering structures and complex systems. They also help explain why failures continue to occur, even as technology advances.

Summary by: Henry Petroski, Professor of Civil Engineering and History, Duke University

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