Redundancy

Redundancy is a concept that refers to the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe.

Overview

In engineering, redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe. In many safety-critical systems, such as fly-by-wire and hydraulic systems in aircraft, some parts of the control system may be triplicated, which is formally termed triple modular redundancy (TMR).

Types of Redundancy

There are several types of redundancy, including hardware, information, time and software redundancy.

Hardware Redundancy

Hardware redundancy is the duplication of physical components. In computer systems, this can be as simple as adding an extra hard drive, or as complex as designing a fault-tolerant system that can continue operation even when a major component or system fails.

Information Redundancy

Information redundancy is the repetition of data in a database or other storage system. This can be used to protect against data loss, as well as to improve the performance of certain operations.

Time Redundancy

Time redundancy involves performing the same operation multiple times. This can be used to check for errors and ensure that the correct result is obtained.

Software Redundancy

Software redundancy is the use of multiple versions of the same software, running on different systems or in different locations. This can be used to protect against software bugs or failures.

See Also

• Fault tolerance
• High availability
• Reliability engineering
• Safety engineering