Which statement best describes normalization of deviance in safety cases?

• A. It causes immediate catastrophic failure
• B. It leads to gradually accepting higher safety risk over time
• C. It is unrelated to safety culture
• D. It only affects maintenance tasks

Answer: (B)

Normalization of deviance is about how people gradually accept higher and higher safety risks because past deviations haven’t yet caused a serious problem. In safety cases, small or occasional deviations from established procedures can become as if they’re normal practice. Over time, this shifts the organization’s perception of risk from “this is risky” to “this is acceptable,” which erodes defenses and alertness. The result is a creeping increase in vulnerability rather than an immediate, obvious failure.

That’s why the best answer says it leads to gradually accepting higher safety risk over time. It captures the subtle, slow shift in behavior and mindset that safety cases warn against. It’s not about an instant catastrophe, it’s about how lax attitudes toward deviations can build up and set the stage for a serious incident. It also isn’t limited to maintenance tasks or unrelated to safety culture; it reflects how safety culture, governance, and daily practices intersect to either strengthen or weaken protective barriers.