Data Migration Fields

1. Description

• What it’s for: A narrative overview of this data migration — what data moves, from which source, to which target, and why.

• What to include:

  • The source system and the target system.
  • What data is being migrated and its significance to the business.
  • Any key constraints or dependencies (e.g. “must complete before go-live”, “depends on DMG-2 completing first”).
  • High-level transformation or cleansing required (detail goes in the Data Mapping tab).

• Example: "All open and historical purchase orders from the legacy ERP are migrated to the new procurement platform. Open orders (status: pending or in-progress) are migrated as active records; historical orders (status: completed or cancelled) are migrated as read-only archive records. Supplier references must be remapped to the new supplier IDs assigned during the Supplier Master migration (DMG-1)."

2. Testing Strategy

• What it’s for: How this migration is tested before go-live.

• What to include:

  • The approach: dry runs, parallel execution, subset testing, full rehearsal.
  • Reconciliation methods: record counts, financial totals, checksum comparisons.
  • Who performs the testing and who signs off on the results.
  • Any automated validation queries or scripts.

• Example: "Three dry runs to be performed in the pre-production environment. Each run includes a full record count reconciliation and a sample of 50 records verified manually by the Finance team. Final sign-off required from the Head of Finance before production migration is approved."

3. Pre-Migration Checks

• What it’s for: The go/no-go gate checks that must pass before the migration begins.

• What to include:

  • Source data quality checks (completeness, referential integrity, no blocking errors).
  • System readiness checks (source system available, target system ready to receive data, dependent migrations complete).
  • Backup confirmation (source system backed up before migration starts).
  • Access and permissions verified.

• Example:

  • All suppliers in the source system have been matched to a target supplier ID (DMG-1 complete)
  • Source ERP is in read-only mode and backup confirmed
  • Target procurement platform is accessible and has passed smoke test
  • Migration user account has confirmed write access to the target Data Set

4. Post-Migration Checks

• What it’s for: The validation steps run after the migration completes to confirm it succeeded.

• What to include:

  • Record count comparison (source count = target count, or documented exceptions).
  • Business reconciliation totals (e.g. total outstanding order value matches).
  • Referential integrity checks in the target system.
  • Sample record spot checks by the business.
  • Any automated validation queries to run.

• Example:

  • Total purchase order count in target = total in source (exceptions logged)
  • Sum of open order values reconciles within £0 variance
  • All purchase order line items have a valid product reference in target
  • Finance team to verify 20 randomly selected orders against source records

5. Rollback Strategy

• What it’s for: What to do if the migration fails — how to restore the pre-migration state.

• What to include:

  • The trigger conditions for invoking rollback (e.g. reconciliation fails, critical validation error).
  • The rollback steps: which systems need to be reverted, in which order, and by whom.
  • How long the rollback window is (the maximum time before rollback must be decided).
  • Any data that cannot be rolled back and how that is handled.

• Example: "If post-migration checks fail, invoke rollback within 2 hours of migration start. Rollback steps: (1) restore target database from pre-migration backup, (2) re-enable source ERP for read-write access, (3) notify stakeholders. Rollback decision authority: Head of IT and Head of Finance jointly. Note: any records manually created in the target during the migration window cannot be automatically rolled back and must be handled case-by-case."

Relationships

Data

Technical Components

Requirements Traceability

Acceptance and Testing

RAID and Work

Reference