Margin of Safety

Margin of safety is a precautionary mental model used to absorb variations, errors and bad luck.

Margin of Safety is a mental model based in engineering that can be used in other aspects of our life on a regular basis. 

For example, think of a tyre that can endure 50000 miles, at what point do you stop using that tyre? The most objective answer to this might be 49999.99 miles, however that is not the most rational thing to do. 

In this case, we need …