Backup Systems (Redundancy)

Summary: The concept of backup systems, also known as redundancy, originated in the field of engineering. Many mechanical systems are created in such a way that if one part of the system fails, the system as a whole will still be able to function due to the presence of backup components. Redundancy and backup plans should play an important role in many decision-making processes for the purpose of risk reduction.

Originator: Jon von Neumann (1903-1957)

Keywords: reliability, reliability engineering, redundancy, independent backup system, mechanical engineering, risk reduction, safety plan, disaster recovery, backup software

Backup systems were first described in the field of mechanical engineering by Jon von Neumann. In his well-known work, Probabilistic Logics and Synthesis of Reliable Organisms from Unreliable Components, Neumann described how computers can be built with redundant parts as a “technique [that] can be used to control error.”[i] In the years to come, redundancy would become an essential concept in designing complex mechanical systems.

The engineering behind aircrafts is a prime example of how engineers use backup systems today. If an airplane experiences any form of mechanical failure while in the sky, this is clearly a major problem. Because of the inherent risk found in air travel, airplanes are built in a mechanically redundant way, with a number of backup systems in place. For example, most airplanes can run on only one engine, even though they have four engines in all. Up to three of these engines could fail, and the airplane would still be able to fly.

It has been argued that the redundancy of back-up systems should be used as a “design paradigm” for all modern technology. From airplanes to computers, from communication systems to emergency preparedness, backup systems should be an essential component of how society designs all important technology.

Backup Systems and Risk Reduction

When considered from the standpoint of making decisions, backup systems are a form of reducing risk in a variety of areas. The decision to include or not include backup systems can have a huge impact on communities, businesses, and individuals.

Backup systems are important to use in mechanical systems as described above, software systems, and for backing up data. Research shows that redundancy in software systems can reduce human error.[ii] And in terms of backup of data, many people know the importance of saving documents in multiple places to reduce the risk of losing information. For example, an important document might be saved on a computer hard drive, an external disc, and an online storage system. Some businesses have backup policies in place to ensure the safety of important documents.

Backup systems are especially important in decisions about emergency preparedness. In natural disasters, backup systems should be put into place to ensure that people have enough fuel, food, and shelter. When performing field work or travel in remote areas, redundancy in communication is important. A group should be able to communicate with the outside world through multiple means such as walkie talkies, cellphones, and flares to ensure help could find them should something go wrong.

Human backup systems are also important to consider.[iii] Are there enough operators to respond to 911 calls? Are there enough policeman to back up their coworkers and enough fireman for an area?

In situations where things could easily go wrong, redundancy is important to decrease the risk of negative outcomes.


[i] Downer, John. (2009). When failure is an option: Redundancy, reliability, and regulation in complex technical systems. Centre for Analysis of Risk and Regulation. Discussion paper No: 53.

[ii] Van den Brand, M. & Groote, J. F. (2015). Software engineering: Redundancy is key.  Science of Computer Programming, 97(1), 75-81.

[iii] Hwang, S. L. & Li, Z. 2016). Human factors in digital systems. A study on human redundancy in execution of computerized emergency operating procedures. International Journal of Industrial Ergonomics, 51, 1-82.