Failure Modes
Hook
Four names, one table. This is the lookup version of the four recurring ways a single automated loop goes wrong on its own — for skimming during an incident, or for checking a proposed loop before it ships, not for learning the ideas for the first time. The fuller version, with a worked scenario behind each name, is Step 12 in Part 5; read that one first if any of the four names below is new to you.
Explanation
Read the table left to right per row: the name a team should use out loud when diagnosing a stuck loop, what tips a team off that this particular mode is live, the shape of the fix, and where the runnable version of that fix will eventually live.
| Failure mode | Symptom | Fix | Linked pattern |
|---|---|---|---|
| Metric-gaming | The headline number keeps improving while people downstream of the loop quietly start working around its output. | A counter-metric: a second number, computed by someone other than the loop and never fed back into it. | see patterns/registry.yaml, ships Day 3 |
| Blind spot | Every individual unit the loop touches looks fine, yet a failure shows up in how two or more of those units interact. | A wider audit loop that reads several units together in one pass, on its own schedule. | see patterns/registry.yaml, ships Day 3 |
| Collision | Two loops each report success, but something downstream broke only on the nights both happened to run close together. | An arbitration edge: a recorded precedence rule stating which loop wins the shared resource. | see patterns/registry.yaml, ships Day 3 |
| Drift | The loop's own numbers hold steady or improve while the thing it's judging has visibly moved on. | A periodic edge back to a human, who resamples current reality and refreshes the reference. | see patterns/registry.yaml, ships Day 3 |
A fast way to tell these apart under pressure: ask whether the loop, given only what it can see and what it's scored on, could ever have caught this itself.
- No, because the score rewards the failure → metric-gaming.
- No, because the evidence lives outside any single run → blind spot.
- No, because another loop is invisible to it → collision.
- No, because the yardstick itself moved → drift.
Related
anti-patterns.md— the governance anti-patterns section names the missing edge behind each of these four modes.