If there is one experience that every person shares in life, it is randomness. We are all subject to events against our will which often render our plans useless. Be it leaving the home in your sundress and suddenly facing rains or phone running out of battery just when you receive an important call.

Our plans can never be perfect, but we can make them better by using a margin of safety.

Mental Mode #3: Margin of Safety

The margin of Safety (or factor of safety) is an engineering concept used to describe the load-carrying capacity of a structure beyond what it is expected to support. It is your safety cushion.

On a windy day, first-time visitors to the Eiffel Tower are often scared by it swaying around. In fact, in 1999, it was once recorded to sway by 13 cm! But you can still trust that it wouldn’t collapse because it was built with a margin of safety to accommodate for stresses well beyond what is usually expected.

Let’s see how you can apply this simple yet widely applicable mental model to other aspects of life.

Personal finance

If you make $2,000 per month and spend 100% of your income, you are left with no funds to tackle emergencies like medical bills from an accident. On the other hand, if you live off just 90% of your income, the remaining $200 contributes towards a buffer that can come in handy in the future.

It gets even more effective as your income rises. Say when your income rises to $10,000 per month, you can still live well on just 50% of your income. Over a couple of years, this would create a safety cushion to fend off even the biggest shocks. On the other hand, if you fall for lifestyle inflation and continue spending 100% income, a big shock can leave you bankrupt no matter how high your income is.

Strength training

When you’re lifting weights, avoid the temptation to squeeze all you got, and leave room for one repetition at least. This would ensure you can account for randomnesses like a wobbly weight or blackout due to oxygen shortage. In general, it will make you confident to perform the whole range of motion without any fear of injury due to bad posture.

Time management

When planning your day, especially with time-blocking, the key to being punctual lies in keeping some buffer for each task. If you want to reach the office by 8 AM and it takes you 10 minutes to reach, do not wait until 7:45 AM to leave home. Instead, leave at 7:30 AM itself so you have a safety cushion of 20 minutes. Not only will it lead to less stress in commute due to random roadblocks, but also give you enough time at the office to plan the day and settle in.

Now a small challenge for you: Can you connect the concept of Margin of Safety with the previously learned models, i.e., Inversion and Second-Order Thinking? Just try😊