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The matrix and the S5 override

A five-by-five likelihood by severity matrix in four bands, with catastrophic severity Critical at any likelihood and a gate and acceptor per band.

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The matrix and the S5 override A five-by-five likelihood-by-severity matrix with Low, Medium, High and Critical bands, the catastrophic severity row on its own track as Critical at any likelihood, and the gate and acceptor for each band. Illustrative scales and bands L1 L2 L3 L4 L5 S5 Critical at any likelihood S4 Medium High High Critical Critical S3 Low Medium High High Critical S2 Low Low Medium Medium High S1 Low Low Low Medium Medium L1 Rare · L2 Unlikely · L3 Possible L4 Likely · L5 Almost certain S1 Negligible · S2 Minor · S3 Moderate S4 Major · S5 Catastrophic What each band triggers Low Registry entry and owner Accept: system owner Medium Eval gate on the linked risk Accept: product owner High Eval gate and runtime guardrail Accept: risk committee Critical Deploy denied Accept: governing body, or no one
The matrix and the S5 override The illustrative five-by-five likelihood-by-severity matrix, with catastrophic severity on its own track as Critical at any likelihood, and the gate and acceptor each band triggers. Rate each risk on the defined scales, then wire each band to its gate. Drawn from chapter 13.

Text alternative

Likelihood: L1 Rare, L2 Unlikely, L3 Possible, L4 Likely, L5 Almost certain. Severity: S1 Negligible, S2 Minor, S3 Moderate, S4 Major, S5 Catastrophic. S5 runs on its own track: any S5 scenario is Critical whatever its likelihood. From L1 to L5, S4 is Medium, High, High, Critical, Critical; S3 is Low, Medium, High, High, Critical; S2 is Low, Low, Medium, Medium, High; S1 is Low, Low, Low, Medium, Medium. Low: a registry entry and owner, accepted by the system owner. Medium: an eval gate on the linked risk, accepted by the product owner. High: an eval gate and runtime guardrail, deploy denied without a current acceptance, accepted by the risk committee with the second line consulted. Critical: deploy denied, accepted by the governing body, or no one. The thresholds are illustrative; calibrate them to your volumes.

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A five-by-five likelihood by severity matrix in four bands, with catastrophic severity Critical at any likelihood and a gate and acceptor per band.
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“The matrix and the S5 override” by Jorge García Aibar, aigovernanceengineer.com (https://aigovernanceengineer.com/figures/risk-matrix), v0.5.0. Licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/).

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*[The matrix and the S5 override](https://aigovernanceengineer.com/figures/risk-matrix) by Jorge García Aibar, aigovernanceengineer.com, v0.5.0. Licensed under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).*