**Purpose:** declares the failure modes you have observed in practice on
the live system, so Bridge can analyze whether your evaluation evidence
covers the failure space honestly.
Required columns:
| Column | Type | Required | Description |
|---|---|---|---|
| `failure_id` | string | yes | stable identifier for this failure mode within your incident registry |
| `failure_description` | string | yes | what happens when this failure mode occurs (≤500 chars) |
| `severity` | enum | yes | one of: `low`, `medium`, `high`, `critical` |
| `frequency_estimate` | enum | yes | one of: `once_observed`, `rare_weekly`, `regular_daily`, `frequent_hourly`, `continuous` |
| `affected_variants` | string (semicolon-separated) | yes | semicolon-separated list of `variant_id` from `unified_variant_comparison.csv` that exhibit this failure |
| `affected_slices` | string (semicolon-separated) | no | semicolon-separated list of `slice_id` from `current_slice_metrics.csv` (omit if cross-slice) |
| `first_observed_date` | ISO-8601 date | yes | when this failure mode was first documented |
| `mitigation_status` | enum | yes | one of: `none`, `partial`, `complete`, `accepted_risk` |
| `notes` | string | no | free-form notes including reproduction recipe |
**Minimum row count:** ≥1 (zero-failure systems are either too new to evaluate or hiding evidence; Bridge will flag)
Example:
failure_id,failure_description,severity,frequency_estimate,affected_variants,affected_slices,first_observed_date,mitigation_status,notes
F001,Pipeline timeout under high concurrency >200 RPS,high,rare_weekly,v_pipeline,geo:us-east;geo:eu-west,2026-04-12,partial,added circuit breaker
F002,Verifier agent hallucinates approval on adversarial input,critical,once_observed,v_pipeline,,2026-05-03,partial,prompt-hardening in progress
F003,Token cost spike when planner+executor enter retry loop,medium,regular_daily,v_pipeline,tenant:enterprise,2026-03-22,accepted_risk,cost monitoring in place
What this CSV is NOT:
**Canonical source:** `bdc-bridge-passport` repository at frozen SHA recorded in `PASSPORT_REPO_PIN.md`.