Engineering a safer world

Innovations in software and technology are creating increasingly complex systems: cars that park themselves; medical devices that automatically deliver drugs; and smartphones with the computing power of desktop computers, to name a few. Such complex systems allow us to do things that seemed difficult or impossible just a few years ago.

But Nancy Leveson, professor of aeronautics and astronautics and engineering systems at MIT, says increasing complexity is also making systems more vulnerable to accidents. What's more, she says, traditional safety engineering approaches are not very effective in keeping new and fast-evolving systems safe. For example, engineers typically evaluate the safety of a system by checking the performance of each of its components.

Leveson argues that safety - particularly in complex systems - depends on more than a system's individual parts.
 
For the past decade, Leveson has been championing a new, more holistic approach to safety engineering. In addition to analysing systems' technical components, her approach - dubbed STAMP, for System-Theoretic Accident Model and Processes - addresses the impacts of human, social, economic and governmental factors on safety.

Last week, Leveson hosted a three-day workshop at which more than 250 safety engineering professionals from around the world gathered to learn about STAMP and to explore the event's theme, ''Engineering a Safer World.'' The event also coincided with the publication of Leveson's new book on the topic, titled `Engineering a Safer World: Systems Thinking Applied to Safety.'

The workshop drew participants from industries, including aviation and automotive engineering, occupational health, missile defence, road tunnel safety, and medicine, some of whom gave presentations during the workshop.
 
In many cases, safety analyses are performed only after an accident has occurred. Several researchers at the workshop presented cases in which they used Leveson's approach to identify causes of accidents.

Daijiang Suo, a graduate student in computer science at Tsinghua University, reconstructed a 2003 train accident that killed 40 people in southwest China. Engineers originally determined that lightning caused a track circuit to malfunction, causing the train to derail. Using Leveson's approach, however, Suo expanded the parameters of safety to include other factors, ultimately attributing the accident in part to communication issues between operators and in part to pressure to keep the train on schedule.
 
Stathis Malakis, an air traffic controller and human factors researcher for the National Technical University of Athens, is analysing the safety of helicopters that provide emergency medical services in Greece. When these helicopters crash, authorities write up accident reports, although Malakis says many reports are not released until much later.