113 Redundancy
Using back-up or fail-safe elements to maintain system performance in the event of failure.
• Redundancy is the most reliable method of preventing catastrophic failure.
• When the causes of failure cannot be anticipated, use different kinds of redundancy; for example, having both a hydraulic and a mechanical brake.
• When the causes of failure can be anticipated, use more of the same kinds of redundancy; for example, using independent strands of fiber to weave a rope.
• When performance interruptions are not tolerable, make redundant elements active at all times; for example, using additional columns to support a roof.
• When performance interruptions are tolerable, make redundant elements passive but available; for example, having a spare tire in the event of a flat tire.
See Also Crowd Intelligence • Factor of Safety • Modularity Saint-Venant’s Principle • Weakest Link
