The intervention chain.
Detect, escalate, decide, intervene. Four stages, one clock. The chain is the mechanism the category turns on, and the place it usually fails.
The four stages.
- 01 Detect
A deviation is identified, not merely produced. Detection is the gap between when a system starts to fail and when a signal reaches anyone who can act.
- 02 Escalate
The signal travels to authority. Each step is usually staffed by someone who can pass the signal on but cannot stop the system. Escalation informs; it does not act.
- 03 Decide
A stop decision is made. If the threshold was agreed in advance, the decision is fast. If it is invented under pressure, the window keeps closing while it is debated.
- 04 Intervene
The system is altered or halted. This is the only stage that changes the outcome, and it requires authority and capability to coincide at the same point.
Where the chain breaks.
Each stage adds latency, and the chain is only as fast as its slowest stage. A failure at any one of the four caps the whole: instant detection cannot recover a decision that waits for a committee, and a clear decision cannot recover an intervention nobody is authorised to perform. This is why measuring controls in isolation is misleading. The chain must be measured end to end, against the reversibility window, with halt authority placed where the deviation is first detected.
How AGDA™ evidences it.
AGDA™ assesses evidence at each stage of the chain, applies an evidence ceiling so a weakly evidenced stage cannot inflate the result, and propagates the weakest stage through to the verdict. The output is a deterministic statement of whether the chain completes before harm becomes irreversible, with the limiting stage named.
Frequently asked questions.
- What is the intervention chain?
- The intervention chain is the sequence of detect, escalate, decide and intervene that must complete within the reversibility window. It is the mechanism Intervention Readiness measures.
- Why does the weakest stage matter most?
- Because the chain is only as fast as its slowest stage. Detection can be instant and authority can be clear, but if the decision waits for a meeting, the whole chain misses the window. This is chain propagation: the weakest stage caps the verdict.
- Does the chain run against a clock?
- Yes. The chain runs against the reversibility window, the interval before harm becomes irreversible. The question is whether detect, escalate, decide and intervene complete before that window closes.