Lesson 4 of 6
Investigating and documenting differences
10 min
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Every reconciliation produces differences in the early mocks. That is the point of the mocks. What separates a well-run migration from a stressful one is how differences are handled: logged at once, classified by cause, owned by a named person, fixed at the source, and re-validated in the next cycle.
Classify by cause
| Cause | Typical symptom | Fix at |
|---|---|---|
| Mapping | Values systematically wrong for a group: all CR30 customers got the wrong payment term | Mapping rules, then reload |
| Timing or cut-off | Documents posted in legacy after the extract; balances differ by those postings | Cut-off procedure; reconcile as a listed reconciling item or re-extract |
| Source data | Legacy data was wrong or inconsistent: duplicate customers, negative stock, asset without depreciation start | Data cleansing in legacy before the next extract |
| Extraction | Records missing from the file; filter too narrow | Extract program, then re-extract |
| Load or configuration | Records rejected or posted to wrong accounts: missing account determination | Configuration via transport, then reload |
| Translation and rounding | Small local currency differences on foreign currency items | Within tolerance: explain; above: check rate type and date |
| Report selection | Reports compared with different parameters | Rerun with identical selections; not a data error |
Causes of differences. The cause decides who fixes it and where.
- Do the two reports use the same selection, date and currency?No → rerun with identical parameters; not a data difference · Yes → next question
- Is the item in the extract?No → extraction or cut-off issue · Yes → next question
- Is the extract value equal to the legacy value?No → extraction or source data issue · Yes → next question
- Is the target value equal to the extract value?No → mapping, load or configuration issue · Yes → recheck the legacy report itself
Reconciling items versus errors
Some differences are not errors. A reconciling item is a known, explained difference with documentary support: for example, three customer payments posted in legacy on cut-off day after the extract ran, which will be posted manually in SAP S/4HANA on day one. A reconciling item has an amount, evidence and a plan. An error is a difference caused by something wrong in data, mapping or process, and it must be fixed. Labeling an error as a reconciling item to make the numbers work is how migration problems reach the auditor.
The difference log
Keep one difference log per migration, in a controlled place such as SAP Cloud ALM or a versioned workbook referenced from it. Each entry records:
- Identifier and cycle: for example D-1910-AR-007, mock 1.
- Check and object: which reconciliation found it, which object and company code.
- Expected versus actual: values and the records affected.
- Amount and currency, and whether it is inside tolerance.
- Cause class and a short root cause statement.
- Owner and due date.
- Resolution: what was changed, where, and in which transport or cleansing task.
- Re-validation: in which cycle the fix was proven, with a reference to the evidence.
- FoundReconciliation breaks; entry created within the same day
- ClassifiedCause class and owner assigned
- Fixed at sourceMapping, cleansing, extract or configuration corrected
- Re-validatedNext mock shows the check passing
- ClosedEvidence linked; reviewer confirms
What would you do?
In mock 2, asset net book values in 1910 match in total but 12 assets show values in the IFRS area that differ from legacy, offset by others. Who should own the difference and how should it be classified first?
- Classify each difference by cause: mapping, timing, source data, extraction, load or configuration, rounding, or report selection.
- Locate a difference by walking legacy, extract and target.
- Reconciling items are explained, evidenced differences; errors must be fixed. Never plug.
- Log every difference with owner, resolution and the cycle in which the fix was re-validated.
Check your understanding · not graded
Lesson check
1. Documents posted in legacy after the extract ran cause a difference. Which cause class is this?
2. What is a reconciling item?
3. The target value differs from the extract, but the extract equals legacy. Where is the problem?
4. W2 Mock 1 AR for 1910 is short by MXN 17,215.28 because items were posted after the extract ran. What was the fix?