Lesson 5 of 5
Auditability of the migration
13 min
After go-live, the opening balances, open items and master data loaded for company code 1910 become part of the foundation of Contoso's consolidated financial statements. External auditors will want to know how they got there. So will internal audit, and so will anyone investigating a payment problem two years later. Auditability means that for every migrated object you can show, from retained evidence, that the data was complete, accurate, authorized and moved under control.
What auditors look for
| Question | Evidence that answers it |
|---|---|
| Was everything in scope migrated? (completeness) | Approved selection rules; source extract control totals; target counts and totals; reconciliation with every difference explained |
| Was it migrated correctly? (accuracy) | Approved mapping specifications; reconciliation of values; sample checks by owners |
| Was it authorized? | Owner approvals of scope and rules; sign-off of each production load |
| Was the process controlled? | Restricted access to load tools and staging data; change control on rules; segregation between those who load and those who validate |
| Do the books tie out? | Opening balances by account and company code match the legacy closing balances; migration clearing accounts net to zero |
Typical audit questions about a migration and the evidence that answers them. Involve internal audit early to confirm what they will expect.
The evidence chain per object
- Scope decisionDecision record with owner and selection rule
- Approved specificationMapping and transformation rules, version and approval date
- Extract control totalsCounts and amounts from the source at extraction time
- Load logsMigration Cockpit messages and record counts for the production load
- ReconciliationSource versus target, differences explained or corrected with approval
- Owner sign-offNamed data owner accepts the object, with date and any accepted exceptions
Build the chain during the mocks, not on go-live weekend. If Mock 3 and the dress rehearsal produce the full evidence pack in the same format the production load will use, go-live evidence is a repeat of a practiced routine. Priya kept a template evidence pack per object and reviewed it after each rehearsal for missing items.
Finance-specific checks
Financial objects need special care. The finance migration for Alternadores del Norte followed the usual pattern: inventory balances, then open receivables and payables, then remaining G/L balances, all against migration clearing accounts that must net to zero. Dan's sign-off pack compared the legacy ERP's trial balance at cutover, mapped to Contoso's chart of accounts, with the opening balances in SAP S/4HANA for company code 1910 (MXN) in the leading ledger 0L, and confirmed that IFRS values in non-leading ledger 2L were established as designed. Subledgers were reconciled to their general ledger accounts on both sides.
| Check | Source (legacy ERP at cutover) | Target (SAP S/4HANA after load) | Pass condition |
|---|---|---|---|
| Trial balance by account, company code 1910 | Closing balances | Opening balances | Equal, or each difference explained and approved |
| Open receivables by customer | Open item list totals | Open item list totals | Equal by company code and currency |
| Open payables by supplier | Open item list totals | Open item list totals | Equal by company code and currency |
| Inventory value by plant | Stock value for plant 1910 Monterrey | Stock value after load | Equal, consistent with the physical count |
| Migration clearing accounts | Not applicable | Balance after all loads | Zero |
Controls over the process
- Access: only named cutover roles can run loads in production; access is granted for the window and removed after.
- Segregation: the people who load data are not the only people who validate it; owners validate their own objects.
- Change control: no rule changes during the production load without a logged, approved emergency change.
- Corrections: post-load corrections are documented, approved and reconciled, never quietly posted to make totals match.
- Retention of evidence: the evidence pack is stored in a controlled location for the period internal audit specifies.
Programs using selective data transition can use reconciliation features built into their tooling; SAP describes Data Transition Validation in SAP Business Transformation Center as comparing source and target snapshots in an audit-proof way. Whatever the tool, the auditor's question is the same: show me that it was complete, accurate, authorized and controlled.
- Is every in-scope object covered by an approved scope decision and specification?Yes → next question · No → close the gap before go-live, or record an accepted exception
- Do extract totals reconcile to target totals, with every difference explained?Yes → next question · No → correct with approval, or document the owner's acceptance
- Has the named owner signed each object, and is the evidence filed in the controlled location?Yes → audit-ready · No → the object is not closed
What would you do?
Three months after company code 1910 went live, the external auditor asks Contoso how its opening receivables balance was established. What is the best answer?
- Auditability means proving completeness, accuracy, authorization and control from retained evidence.
- Keep an evidence chain per object: scope decision, approved specification, extract totals, load logs, reconciliation, owner sign-off.
- Opening balances must tie to legacy closing balances; migration clearing accounts must be zero.
- Practice the evidence pack in the mocks; control access, segregation, changes and corrections during the load.
Check your understanding · not graded
Lesson check
1. Migration evidence for auditors should include:
2. What must the migration clearing accounts show after all finance loads?
3. Why build the evidence pack during mocks?
4. Which control supports segregation of duties in migration?