What do a spare tire, a second job, and extra bridge struts have in common?
Answer: They are all forms of Redundancy, which is a Mental Model that refers to ‘over-engineering’ a system to reduce the chances of failure.
Redundancy can be added to all kinds of systems and it can help you prevent disaster down the road. Read on to learn about redundancy in engineering and other ways backups play an important part of your life.
Redundancy In Engineering: What Is It And Where Is It Found?
Typically redundancy refers to the process of adding ‘extra’ instances of critical components to a system so that one can take over for another if something breaks.
There are a number of examples in engineering, from back-up controls and power systems in airplanes to extra hard drives and power supplies in computers used in datacenters.
The Internet itself is a prime example of Redundancy as most of its core transport networks and popular sites have been designed to withstand the failure of individual links or nodes.
Applications Outside Engineering
Redundancy is a concept from Charlie Munger’s System of Mental Models that can be applied to other areas as well. Once you start looking for ways to add Redundancy to the systems in your life you will start to see such opportunities more and more.
Simply looking around the home can get you started:
- What happens if the power goes out?
- Install a generator.
- What happens if my sump pump fails during a rainstorm?
- Install a backup sump pump.
- What happens if my furnace dies in the middle of winter?
- Purchase a space heater.
Not Always Worthwhile
The list above brings up two important points about Redundancy:
- Adding Redundancy to a system almost always increases the cost of the overall system.
- The severity of the failure scenario will vary tremendously across a range of systems.
So like anything else you can have too much of a good thing, or in this case add too much Redundancy.
With this is mind it is important when thinking about adding Redundancy to a system to consider the cost of adding it as well as the consequences of a failure.
- What could be lost if something breaks?
- What would it cost to add some sort of failsafe?
- Does the cost of adding Redundancy outweigh the potential loss?
Once you start seeing the potential for Redundancy in systems it can become easy to go overboard and add it in ways that provides no real value.
Redundancy in … Personal Finance?
Looking beyond the home there a number of other opportunities for Redundancy in daily life. One of my favorite examples applies to an area well outside the realm of engineering: personal finance.
Think about your income as a system:
- How are you bringing in money?
- How many sources are there?
- What happens if a primary source fails?
- What if you are part of a dual-income couple?
- How does this change if both partners work for the same organization?
Income isn’t often associated with Redundancy but it deserves some thought.
Based on this a number of personal finance advisers are now taking this into account, recommending that dual-income couples not work for the same organization in case there is a shutdown of some sort.
Some advisers go farther and recommend that everyone try to have other streams of income beyond their primary source.
Where Else is it Used or Needed?
Do any of these have redundancy? Should they?
- Engagement rings (ask a jeweler about the number of prongs used in various settings)
- Telephone (what if you need to call 911?)
- Fire exits (what if you sleep on the second floor or higher?)
Just thinking about these can get you in the right frame of mind. Leave a comment below with an idea for someplace where redundancy can be helpful.
Also, you can find more Mental Models by reading the books in the Charlie Munger Reading List.