# redundancy (engineering)

A second system whose parameter has a window that overlaps the first, so that drift in the parameter can leave one window while remaining in the other.

- Computed level: L12 (depth in the emergence graph, not abstraction)
- Status: review  ·  Domain: engineering  ·  Arena: engsys

## Emergence
**Emerges from:** [window](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-window.range), [drift](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-drift.aimless), [parameter](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-parameter.condition), [second](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-second.temporal), [time](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-time.dimension), [system](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-system.organized)

**Through:** Two organized systems maintain function through parameter drift because a parameter can leave the range of the first but remain within the range of the second, enabled by temporal succession and overlapping windows in time.

**Novel properties:**
- overlapping tolerance bands
- continuous functionality despite drift
- temporal system succession

## Examples
- The Hubble Space Telescope's gyroscopes include backup units that activate when primary gyro drift exceeds operational thresholds. *(engineering)*
- The human body maintains blood pH between 7.35 and 7.45, with kidneys and lungs providing overlapping regulatory mechanisms. *(biology)*
- Amazon Web Services routes traffic through multiple availability zones, each with independent power and cooling systems. *(computing)*

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*Canonical: https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-redundancy.engineering*  
*Structured data: https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-redundancy.engineering.json*  
*Every definition provably resolves to space, time, energy and pattern.*