Universal journal

In a system conversion, most of Contoso Motor Co.'s ECC 6.0 EHP 8 system comes across as it is: configuration, custom code, history and users. Finance is the big exception. The Software Update Manager (SUM) converts the system technically, but the finance data then has to be migrated into a new data model. SAP's conversion guide says it plainly: after the technical conversion you migrate the migration-relevant Customizing and the general ledger, asset accounting, controlling and material ledger data to the new structure. This course explains that move well enough for a migration specialist, test lead or architect to plan it, test it and get it signed off.

One table instead of many

In ECC, a single posting was written to several stores: the accounting document (header and line items), general ledger totals and line item tables, separate controlling line items and totals, asset accounting values, the material ledger and profitability analysis. Each module kept its own copy, and month-end included proving that those copies agreed. SAP S/4HANA writes actual line items to one table, the universal journal (technical name ACDOCA). G/L, controlling, asset accounting, material ledger and margin analysis information sit on the same line item.

The doubled-up stores are what the conversion has to merge. SAP's own training on downtime-optimized conversion uses this as its example of data conversion: the old general ledger totals and line item tables merge into ACDOCA, and the inventory management header and item tables merge into a new material document table. The merge has to produce the same balances and open items the business had the night before. Proving that is the subject of lesson 4.

What stays, what goes

• Accounting document headers stay; the line items are also written to the universal journal.
• Old totals and index tables (open items and cleared items by account) are no longer stored. Reads are redirected to compatibility views that compute the same answer from the line items, so most standard reports and much custom read logic keep working.
• Custom code that writes to the old tables must change. Code that reads them can be slow. Both show up in custom code analysis and in performance tests.
• Ledgers carry over. Contoso keeps US GAAP in leading ledger 0L and IFRS in non-leading ledger 2L, and both are filled in the universal journal.
• History stays. A conversion keeps every year of postings, which is one reason Contoso chose it over a new implementation.

Why this matters for testing

The impact reaches past finance users. A custom aging report written in 2009 may still run, now through a compatibility view, but return different totals if it relied on a table the conversion no longer fills. An interface to a bank or tax engine may select from an old table. A month-end job may call a classic asset transaction that no longer exists. None of this is visible on a converted screen, which is why the test lead needs to understand the data model change, not just the new apps.

One more consequence: SAP S/4HANA Cloud Public Edition is never reached by conversion, so nothing in this course applies there. Public Edition customers load balances and open items with migration tools into a new system.

Worked example: one sale in the universal journal

Contoso ships 50 × CMC-ALT-100 to Great Lakes Fleet Services on outbound delivery 80001234 (sales order 1000457) and bills it with invoice 90001877: 50 × 240.00 = 12,000.00 USD, tax-exempt. The goods issue values the stock at the Detroit standard cost of 150.00, so cost of goods sold is 7,500.00 USD. In SAP S/4HANA, the two journal entries produce these universal journal lines, each written once per ledger (0L and 2L):

In ECC the same sale wrote accounting line items, new general ledger line items and totals, a material document and, if used, profitability analysis line items, each in its own table. After conversion a tester can check the whole sale in one place: in Display Line Items in General Ledger (F2217) or with the classic line item reports, confirm that all four lines exist in both ledgers, that every line carries profit center CMC-FLEET, and that margin by customer and product shows 4,500.00. One design decision belongs here too: if ECC used costing-based profitability analysis, it remains available in SAP S/4HANA but keeps its own tables outside the universal journal, so decide early whether Contoso moves to margin analysis (account-based) and test the reports that depend on that choice.