ANSWER
How do you define an equivalence contract before cutover?
Reviewed .
An equivalence contract defines, before dual-run, which outputs from the legacy system and replacement will be compared, what tolerance is acceptable for each field or rule, what blocks cutover, which exceptions can be approved and who signs the decision. It avoids a generic accuracy rate: a small difference can be material while a large formatting difference may be irrelevant.
Step by step
- List outputs, critical fields and business rules to compare.
- Define tolerance by field and risk class, not one global percentage.
- Pre-classify blockers, material differences and cosmetic differences.
- Name an owner, expiry and compensating action for every approved exception.
- Set the observation window, approvers, minimum evidence and rollback conditions.
How an agent does this
At AgenticosCore, the Equivalence Contract guides Parallel. Every comparison and exception enters the Trail; House Rules prevent progression outside the criteria; and Brake keeps rollback operationally accessible.
Frequently asked questions
What match percentage is enough?
There is no universal percentage. The contract separates fields and rules by materiality. Any variance may block some items, while documented tolerance is appropriate for others.
Who approves an exception?
The risk owner named before dual-run. Every exception needs rationale, expiry and a compensating action in the Evidence Pack.
Primary sources
- AI RMF Core — NIST