Authors: Wears, Robert L., and L. Kendall Webb.
Publication: Resilience engineering in practice 2 (2014): 33-46.

Things that never happened before happen all the time” Carl Sagan (1993)

‘Surprise’ underpins all resilience engineering theory and applications. The goal of resilience is to manage unexpected and unpredictable events in a successful and positive way, and the word surprise, by and large, encapsulates anything unexpected. This means the ways that experts think about “surprise”, understand what it is, and then deal with it helps establish a basis for designing resilient systems. In this book chapter, Wears & Kendall discuss the nature of surprise and provide a taxonomy of different surprises, i.e., situational and fundamental surprises, that experts experience and design systems to manage. Situational surprises are when unexpected events occur that do not challenge current understandings for how systems work, where fundamental surprises upend pre-existing notions of how systems work. For example, if you buy a lottery ticket, your numbers are picked, and you win, this is a situational surprise. Since the chances of winning the lottery were so low, you are surprised you won, but the act of winning is an expected outcome from buying a lottery ticket. On the other hand, if you won the lottery without buying a ticket, you may encounter a surprise that fundamentally changes your understanding of the entire lottery system. Although these examples are unrelated to sociotechnical systems, resilience requires being able to successfully manage both events. Wears & Kendall demonstrate the differences between these surprises and discuss different kinds of response through an example involving an IT hardware failure (situational surprise) that revealed a misunderstanding of restrictions to IT system root access (fundamental surprise). Taken together, the chapter offers a useful language of surprise to help describe the kinds of events that systems must be resilient to.