While it’s important to have backups in failure cases. It’s important to also consider the impact backups have in contributing to other failure cases.
Another example, people often wonder why airlines do not equip passengers with parachutes in the case of a crash. The answer is that people do not know how to use them, and would likely injure or kill themselves. Furthermore, they wouldn’t help in the period of flight where accidents are most likely to happen, which is take off and landing [2].
Disasters are a systems problem. And when looking to mitigate, we need to consider the efficacy of the mitigation and the total influence of mitigation’s on contributing to the likelihood of other failure cases.
[1] https://www.smithsonianmag.com/history/eastland-disaster-kil...