I think it tends to come up more in fields, such as aeronautical engineering, where there is a safety tradeoff. If you make the plane heavier, it may be safer

I think it tends to come up more in fields, such as aeronautical engineering, where there is a safety tradeoff. If you make the plane heavier, it may be safer from material failure, but now there may be less margin for error by the pilot because the plane does not respond the same. You have traded one kind of risk against another. I remember being present when a friend who was a civil engineer heard that they used a safety factor of only 1.5 in aeronautical engineering, and she was kind of shocked it was so low; when you don't have to fly the thing, you can afford to make the factor significantly higher.