Redundancy

In engineering, redundancy is the duplication of critical components of a system with the intention of increasing reliability of the system. In safety-critical systems, such as fly-by-wire aircraft, some parts of the control system may be triplicated. An error in one component then may then be out-voted by the other two. See safety engineering.

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In information theory, redundancy is the number of bits used to transmit a message minus the number of bits of actual information in the message. Data compression is a way to eliminate such redundancy.

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See also:

• Tautology
• Pleonasm

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In employment law, redundancy is the dismissal of an employee when his or her job becomes unnecessary. UK redundancy law allows three reasons for redundancy:

1. Total cessation of the employer's business (whether permanently or temporarily)
2. Cessation of business at the employee's workplace
3. Reduction in the number of workers required to do a particular job.

The law requires the employer to make a statutory redundancy payment, which is tax-free and is based on the employee's length of service, as long as the employee has served a minimum of two years. The employee is not allowed to claim redundancy if he or she was offered an alternative position with similar salary, status and responsibilities.