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Model

Loop gain

Stability is a ratio, capacity is a level, and only the ratio decides whether you come back.

Branching factor
units of further work each unit of degraded work creates

Recurring principle: Local optimizations compose badly

How it behaves

One input on the horizontal axis, the others held fixed.

Data table
Total work a disturbance causes, by loop gain
Gain RTotal work ÷ the disturbance
01×
0.0121.01×
0.0251.03×
0.0371.04×
0.0491.05×
0.0611.07×
0.0741.08×
0.0861.09×
0.0981.11×
0.111.12×
0.1231.14×
0.1351.16×
0.1471.17×
0.1591.19×
0.1711.21×
0.1841.23×
0.1961.24×
0.2081.26×
0.2211.28×
0.2331.3×
0.2451.32×
0.2571.35×
0.2691.37×
0.2821.39×
0.2941.42×
0.3061.44×
0.3191.47×
0.3311.49×
0.3431.52×
0.3551.55×
0.3671.58×
0.381.61×
0.3921.64×
0.4041.68×
0.4161.71×
0.4291.75×
0.4411.79×
0.4531.83×
0.4661.87×
0.4781.91×
0.491.96×
0.5022.01×
0.5142.06×
0.5272.11×
0.5392.17×
0.5512.23×
0.5642.29×
0.5762.36×
0.5882.43×
0.62.5×
0.6132.58×
0.6252.66×
0.6372.75×
0.6492.85×
0.6612.95×
0.6743.07×
0.6863.18×
0.6983.31×
0.713.45×
0.7233.61×
0.7353.77×
0.7473.96×
0.7594.16×
0.7724.38×
0.7844.63×
0.7964.91×
0.8085.22×
0.8215.58×
0.8335.99×
0.8456.46×
0.8577.02×
0.877.68×
0.8828.47×
0.8949.46×
0.90610.7×
0.91912.3×
0.93114.5×
0.94317.6×
0.95622.5×
0.96831×
0.9850×

Worked examples, recomputed

Every number the mechanisms quote for this relationship is recomputed from it, so none of them disagrees with it.

Where it appears

Each mechanism states it in its own names. The general symbol each name stands for is shown with it.