# just in time (threshold)

*Ordinarily means:* Happening at the right moment, not early or late.

A parameter that has drifted so close to a wall that any further change will push it outside the window, making maintenance impossible despite appearing sufficient until the moment it fails.

- Computed level: L15 (depth in the emergence graph, not abstraction)
- Status: review  ·  Domain: operational_resilience

## Emergence
**Emerges from:** [parameter](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-parameter.condition), [drift](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-drift.aimless), [wall](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-wall.range-end), [maintenance](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-maintenance.upkeep), [window](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-window.range), [margin](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-margin.spatial)

**Through:** The phrase reports a system operating with zero margin, where optimization has eliminated buffer and left no room for drift—thus the wall is near and the window is closing.

**Novel properties:**
- temporal_precision_as_vulnerability
- efficiency-induced_fragility

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