ORIGINAL RESOURCE · V1.0
Equivalence Contract template for dual-run
An Equivalence Contract turns “looks the same” into versioned, signable criteria. Complete it before the first dual-run and change it only with an owner, rationale and new version.
Reviewed .
1. Scope and baseline
Bound one comparable unit instead of trying to prove an entire application in one rule.
- Process, owner and approver
- Baseline window and source
- Inputs, outputs and systems of record
- Volume, seasonality and known exclusions
2. Comparison rules
Every rule needs a formula, unit, tolerance and severity.
- Matching key
- Allowed transformations
- Absolute and percentage tolerance
- Blocker, approved-exception and informational-difference criteria
3. Exit criteria
Define what ends the parallel run before reviewing results.
- Minimum execution count
- Zero blockers or explicitly approved exceptions
- Rollback tested
- Evidence Pack reviewed
- Signatures and decision validity
4. Change control
Do not move the goalposts during the test.
- Contract version
- Reason and author for each change
- Impact on previous runs
- New approval when tolerance or scope changes
TEMPLATE · This is not customer evidence or legal, accounting or security advice. Adapt it with the owners accountable for the real process.