Redundancy is an idea from Engineering that refers to the process of including extra components within a system such that they can be brought into use in the case of a failure so that the system continues to function.
By implementing redundancy within a system we can greatly reduce the chances of the system itself breaking down. Or if the system does fail, backups can be used to get it functioning again as quickly as possible.
The key idea is that redundancy is a way to reduce or eliminate the potential negative impact of a system failing.
- The spare tire in a car
- A family with two income streams
- Backup controls and power systems in airplanes
- Backup generators for homes and businesses
- Extra hard drives and power supplies in data-center computers
Why It Is Useful
Adding redundancy to a system can help keep it from failing at a critical moment.
Case 1: Having a spare tire in your car (yes a car is a system) can keep you from being stranded at the side of the road.
Of course, these days people are more likely to use their cell phone to call for assistance than try to replace their own tire ... but that's still a form of backup!
Complete system failure would be for your car to never be usable again, ever. So each plan you have in place for how you would handle a flat tire or other breakdown is a type of backup.
Case 2: A single-income family can be at risk if the wage-earner loses their job.
Adding a second source of income, whether it is a second job or a second wage-earner, can reduce the chances of system failure (in this case not being able to pay the bills).
Case 3: Airplanes are designed with a massive amount of redundancy, including backup controls, power systems, and even engines.
There are even two pilots, just in case!
Case 4: The Internet has many layers of redundancy. It was built from the ground up specifically to be able to detect failures and find other ways to keep transmitting data.
For example, the servers in Internet data-centers usually have spare hard drives and power supplies built in so they can keep functioning without losing data even if internal components die completely.
The transport links the Internet uses to transmit data are usually redundant as well. Protocols are in place such that if the best path from point A to point B becomes unavailable, the next best path will be used instead.
How It Fits Into The Latticework
Redundancy is actually one of the Mental Models Charlie has specifically mentioned:
And, of course, the engineering idea of a backup system is a very powerful idea.
For starters, Redundancy can impact the Equilibrium of a system. Think about what happens to the stock market when they have a computer 'glitch' ... usually it becomes mass chaos for a short while.
On the other hand, Base Rates can help us determine how much Redundancy may be needed in a system, if any. If a particular system only has a .000001% chance of failing, then maybe it isn't worth worrying about Redundancy.
It can also tie in with Constraints. If a particular bottleneck in a system cannot be optimized and improved, perhaps it is an ideal candidate for Redundancy to at least make sure it is always operating at maximum capacity.
Think about some of the important systems in your life and try to imagine what would happen if each failed in some way. What is the impact? How bad are the consequences? Is it just an inconvenience, or does it cause a major negative impact?
For example, Redundant systems I have recently implemented include:
- adding a backup sump pump so my basement doesn't flood
- creating an emergency fund so I can still pay the bills if I lose my source of income
- purchasing both a fire ladder and a fire extinguisher for my bedroom as I have doubts about my ability to leap out the window of a burning building and land gracefully ...
- Wikipedia: Redundancy in Engineering
Please share your thoughts on this Mental Model or the post itself in the comments below!