What changed from ECC to SAP S/4HANA
Key simplifications for procurement and inventory: Business Partner mandatory, MATDOC inventory model, Material Ledger mandatory, MRP Live, 40-character material numbers, Fiori apps and situation handling, flexible workflow, new output management, and Central Procurement.
- Simplification Item Catalogue lists every functional change per release.
- LE-WM is not the target architecture — move to EWM or Stock Room Management.
- Many MB* transactions are replaced by MIGO; ME21/ME51 by ME21N/ME51N.
- T-codes & apps
/SDF/RC_START_CHECK (readiness checks)Fiori Apps Reference Library
MM integration with FI, CO, SD, PP, QM, PM & EWM
MM sits in the middle of the logistics landscape: FI through account determination and invoices, CO through account assignments, SD via STOs and third-party, PP via MRP and goods movements, QM via inspection lots and stock types, and EWM via storage locations mapped to warehouse numbers.
- QM: inspection type 01 at GR, usage decision posts 321/350.
- EWM: deliveries are distributed to EWM based on storage location → warehouse number assignment.
- PM: maintenance orders create reservations and PRs for non-stock items.
- T-codes & apps
OBYCQA32/SCWM/MON
IDocs, EDI & third-party interfaces
Supplier and 3PL integration typically uses IDocs or APIs: ORDERS (PO), ORDRSP (confirmation), DESADV (ASN → inbound delivery), INVOIC (invoice), WMMBXY (goods movements from external WMS) and SHPCON/SHPORD for 3PL.
- Partner profiles (WE20) and ports (WE21) define who receives which message.
- WE02/WE05 monitor IDocs; BD87 reprocesses; WE19 test tool.
- SAP Business Network (Ariba) is the standard cloud alternative for supplier collaboration.
- T-codes & apps
WE02WE05WE19WE20WE21BD87
Data migration & master-data validation
S/4HANA uses the SAP S/4HANA Migration Cockpit ('Migrate Your Data' app) with migration objects for suppliers (BP), materials, info records, open POs, inventory balances, contracts and more. Validation and reconciliation sign-off are as important as the load.
- Typical sequence: org data → BP → materials → info records/source lists → contracts → open POs → stock.
- Load stock with 561 at the right valuation and reconcile against the legacy GL.
- Use mock loads (at least two) with business validation before cut-over.
- T-codes & apps
Fiori: Migrate Your DataLTMOMMB52MB5L
Functional design, testing, cut-over & hypercare
Delivery runs from workshops and fit-to-standard to functional specifications, configuration, unit and integration testing, UAT, cut-over and hypercare. Good MM delivery is mostly about traceability: requirement → design → configuration → test case → sign-off.
- Write test cases per end-to-end process (P2P, STO, subcontracting) not per transaction.
- Cut-over checklist: open PO conversion, stock freeze, GR/IR reconciliation, interface switch.
- Hypercare: daily defect triage, IDoc monitoring, MRBR blocked invoices, user support.
- T-codes & apps
SAP Solution Manager / Cloud ALMHP ALMServiceNow
Plan the MM cut-over
Your plant goes live on 1 April. Draft the MM cut-over steps for the last week of March: what is frozen, what is migrated, who validates, and what is checked on day one.
Interview-style questions
Name three IDoc message types used in procurement.
ORDERS (PO), ORDRSP (order confirmation), DESADV (ASN/delivery notification), INVOIC (invoice).
Which tool replaced LSMW/LTMC for S/4HANA data migration?
The SAP S/4HANA Migration Cockpit, accessed through the 'Migrate Your Data' Fiori app (LTMOM for object modelling).
What is the target architecture for warehouse management in S/4HANA?
SAP EWM (embedded or decentralised); LE-WM is available only under compatibility scope, with Stock Room Management as a simple alternative.